








                        XTerm Control Sequences


                               Edward Moy
                   University of California, Berkeley

                               Revised by

                             Stephen Gildea
                          X Consortium (1994)

                             Thomas Dickey
                      XFree86 Project (1996-2006)
                    invisible-island.net (2006-2026)
               updated for XTerm Patch #407 (2026/02/16)




Definitions

Many controls use parameters, shown in italics.  If a control uses a
single parameter, only one parameter name is listed.  Some parameters
(along with separating ;  characters) may be optional.  Other characters
in the control are required.

C    A single (required) character.

Ps   A single (usually optional) numeric parameter, composed of one or
     more digits.

Pm   Any number of single numeric parameters, separated by ;
     character(s).  Individual values for the parameters are listed with
     Ps .

Pt   A text parameter composed of printable characters.


Control Bytes, Characters, and Sequences

ECMA-48 (aka "ISO 6429") documents C1 (8-bit) and C0 (7-bit) codes.
Those are respectively codes 128 to 159 and 0 to 31.  ECMA-48 avoids
referring to these codes as characters, because that term is associated
with graphic characters.  Instead, it uses "bytes" and "codes", with
occasional lapses to "characters" where the meaning cannot be mistaken.

Controls (including the escape code 27) are processed once:

o   This means that a C1 control can be mistaken for badly-formed UTF-8
    when the terminal runs in UTF-8 mode because C1 controls are valid
    continuation bytes of a UTF-8 encoded (multibyte) value.

o   It is not possible to use a C1 control obtained from decoding the
    UTF-8 text, because that would require reprocessing the data.
    Consequently there is no ambiguity in the way this document uses the
    term "character" to refer to bytes in a control sequence.

The order of processing is a necessary consequence of the way ECMA-48 is
designed:

o   Each byte sent to the terminal can be unambiguously determined to
    fall into one of a few categories (C0, C1 and graphic characters).

o   ECMA-48 is modal; once it starts processing a control sequence, the
    terminal continues until the sequence is complete, or some byte is
    found which is not allowed in the sequence.

o   Intermediate, parameter and final bytes may use the same codes as
    graphic characters, but they are processed as part of a control
    sequence and are not actually graphic characters.

o   Eight-bit controls can have intermediate, etc., bytes in the range
    160 to 255.  Those can be treated as their counterparts in the range
    32 to 127.

o   Single-byte controls can be handled separately from multi-byte
    control sequences because ECMA-48's rules are unambiguous.

    As a special case, ECMA-48 (section 9) mentions that the control
    functions shift-in and shift-out are allowed to occur within a 7-bit
    multibyte control sequence because those cannot alter the meaning of
    the control sequence.

o   Some controls (such as OSC ) introduce a string mode, which is ended
    on a ST  (string terminator).

    Section 9 of ECMA-48, like DEC STD 070, chapter 3, goes into detail
    to explain that when processing 8-bit controls, the eighth bit of
    each byte is ignored.  This applies to the content of APC, DCS, OSC,
    and PM strings, as well as to the terminating bytes such as the two-
    byte string terminator.  Quoting from the latter, 3.5.4.5 GR Graphic
    Characters within Control Strings:

        GR (8-bit) graphic characters in APC, OSC, and PM control
        strings will be treated as their 7-bit equivalent (the eighth
        bit will be ignored).

        GR (8-bit) graphic characters are permitted within Device
        Control Strings, and the graphic character's interpretation will
        be dependent on the internal control string format.  When they
        occur in the introducer sequence to a Device Control String, the
        eighth bit will be ignored, and they will be treated as their
        7-bit equivalent.  (Note that this is the same way 8-bit graphic
        characters are handled within control sequences.)

    The reason for that is because ECMA-48 presents 7-bit controls as an
    alternative to 8-bit controls.  It says this:

        The control functions defined in this Standard can be coded in a
        7-bit code as well as in an 8-bit code; both forms of coded
        representation are equivalent and in accordance with Standard
        ECMA-35.

    and in turn, ECMA-35 9.1 says

        A 7-bit code shall have a structure which is based on a 7-bit
        code table arranged in separate areas as follows (see figure 7):

    In short, a standard-compliant implementation of ECMA-48 ignores the
    eighth bit of bytes in control strings other than the C1 controls.
    XTerm does this.

    ECMA-48 describes only correct behavior, telling what types of
    characters are expected at each stage of the control sequences.  It
    says that the action taken in error recovery is implementation-
    dependent.  XTerm decodes control sequences using a state machine.
    It handles errors in decoding i.e., unexpected characters, by
    resetting to the initial (ground) state.  That is different from the
    treatment of unimplemented (but correctly formatted) features.

    If an application does not send the string terminator, that is also
    an error from the standpoint of a user.  To accommodate users of
    those applications, xterm has resource settings which allow
    workarounds:

    o   The Linux console's palette sequences do not use a string
        terminator.  The brokenLinuxOSC resource setting tells xterm to
        ignore those particular sequences.

    o   The terminal should accept single-byte controls within the
        string.  But some applications omit a string terminator, like
        the Linux console.  The brokenStringTerm resource setting tells
        xterm to exit string mode if it decodes a common control
        character such as carriage return before the string terminator.


C1 (8-Bit) Control Characters

The xterm program recognizes both 8-bit and 7-bit control characters.
It generates 7-bit controls (by default) or 8-bit if S8C1T is enabled.
The following pairs of 7-bit and 8-bit control characters are
equivalent:

ESC D
     Index (IND  is 0x84).

ESC E
     Next Line (NEL  is 0x85).

ESC H
     Tab Set (HTS  is 0x88).

ESC M
     Reverse Index (RI  is 0x8d).

ESC N
     Single Shift Select of G2 Character Set (SS2  is 0x8e), VT220.
     This affects next character only.

ESC O
     Single Shift Select of G3 Character Set (SS3  is 0x8f), VT220.
     This affects next character only.

ESC P
     Device Control String (DCS  is 0x90).

ESC V
     Start of Guarded Area (SPA  is 0x96).

ESC W
     End of Guarded Area (EPA  is 0x97).

ESC X
     Start of String (SOS  is 0x98).

ESC Z
     Return Terminal ID (DECID is 0x9a).  Obsolete form of CSI c  (DA).

ESC [
     Control Sequence Introducer (CSI  is 0x9b).

ESC \
     String Terminator (ST  is 0x9c).

ESC ]
     Operating System Command (OSC  is 0x9d).

ESC ^
     Privacy Message (PM  is 0x9e).

ESC _
     Application Program Command (APC  is 0x9f).


These control characters are used in the vtXXX emulation.


VT100-related terminals

In this document, "VT100" refers not only to VT100/VT102, but also to
the succession of upward-compatible terminals produced by DEC (Digital
Equipment Corporation) from the mid-1970s for about twenty years.  For
brevity, the document refers to the related models:
  "VT200" as VT220/VT240,
  "VT300" as VT320/VT340,
  "VT400" as VT420, and
  "VT500" as VT510/VT520/VT525.

Most of these control sequences are standard VT102 control sequences,
but there is support for later DEC VT terminals (i.e., VT220, VT320,
VT420, VT510), as well as ECMA-48 and aixterm color controls.  The only
VT102 feature not supported is auto-repeat, since the only way X
provides for this will affect all windows.

There are additional control sequences to provide xterm-dependent
functions, such as the scrollbar or window size.  Where the function is
specified by DEC or ECMA-48, the mnemonic assigned to it is given in
parentheses.

The escape codes to designate and invoke character sets are specified by
ISO 2022 (see that document for a discussion of character sets).

Many of the features are optional; xterm can be configured and built
without support for them.


VT100 Mode


Single-character functions

BEL       Bell (BEL  is Ctrl-G).

BS        Backspace (BS  is Ctrl-H).

CR        Carriage Return (CR  is Ctrl-M).

ENQ       Return Terminal Status (ENQ  is Ctrl-E).  Default response is
          an empty string, but may be overridden by a resource
          answerbackString.

FF        Form Feed or New Page (NP ).  (FF  is Ctrl-L).  FF  is treated
          the same as LF .

LF        Line Feed or New Line (NL).  (LF  is Ctrl-J).

SI        Switch to Standard Character Set (Ctrl-O is Shift In or LS0).
          This invokes the G0 character set (the default) as GL.
          VT200 and up implement LS0.

SO        Switch to Alternate Character Set (Ctrl-N is Shift Out or
          LS1).  This invokes the G1 character set as GL.
          VT200 and up implement LS1.

SP        Space.

TAB       Horizontal Tab (HTS  is Ctrl-I).

VT        Vertical Tab (VT  is Ctrl-K).  This is treated the same as LF.


Controls beginning with ESC

This excludes controls where ESC  is part of a 7-bit equivalent to 8-bit
C1 controls, ordered by the final character(s).

ESC SP F  7-bit controls (S7C1T), VT220.  This tells the terminal to
          send C1 control characters as 7-bit sequences, e.g., its
          responses to queries.  DEC VT200 and up always accept 8-bit
          control sequences except when configured for VT100 mode.

ESC SP G  8-bit controls (S8C1T), VT220.  This tells the terminal to
          send C1 control characters as 8-bit sequences, e.g., its
          responses to queries.  DEC VT200 and up always accept 8-bit
          control sequences except when configured for VT100 mode.

ESC SP L  Set ANSI conformance level 1, ECMA-43.

ESC SP M  Set ANSI conformance level 2, ECMA-43.

ESC SP N  Set ANSI conformance level 3, ECMA-43.

ESC # 3   DEC double-height line, top half (DECDHL), VT100.

ESC # 4   DEC double-height line, bottom half (DECDHL), VT100.

ESC # 5   DEC single-width line (DECSWL), VT100.

ESC # 6   DEC double-width line (DECDWL), VT100.

ESC # 8   DEC Screen Alignment Test (DECALN), VT100.

ESC % @   Select default character set.  That is ISO 8859-1 (ISO 2022).

ESC % G   Select UTF-8 character set, ISO 2022.

ESC ( C   Designate G0 Character Set, VT100, ISO 2022.
          Final character C for designating 94-character sets.  In this
          list,
          o   0 , A  and B  were introduced in the VT100,
          o   most were introduced in the VT200 series,
          o   a few were introduced in the VT300 series, and
          o   a few more were introduced in the VT500 series.
          The VT220 character sets, together with a few others (such as
          Portuguese) are activated by the National Replacement
          Character Set (NRCS) controls.  The term "replacement" says
          that the character set is formed by replacing some of the
          characters in a set (termed the Multinational Character Set)
          with more useful ones for a given language.  The ASCII and DEC
          Supplemental character sets make up the two halves of the
          Multinational Character set, initially mapped to GL and GR.
          The valid final characters C for this control are:
            C = A  -> United Kingdom (UK), VT100.
            C = B  -> United States (USASCII), VT100.
            C = C  or 5  -> Finnish, VT200.
            C = H  or 7  -> Swedish, VT200.
            C = K  -> German, VT200.
            C = Q  or 9  -> French Canadian, VT200.
            C = R  or f  -> French, VT200.
            C = Y  -> Italian, VT200.
            C = Z  -> Spanish, VT200.
            C = 4  -> Dutch, VT200.
            C = " >  -> Greek, VT500.
            C = % 2  -> Turkish, VT500.
            C = % 6  -> Portuguese, VT300.
            C = % =  -> Hebrew, VT500.
            C = =  -> Swiss, VT200.
            C = ` , E  or 6  -> Norwegian/Danish, VT200.
          The final character A  is a special case, since the same final
          character is used by the VT300-control for the 96-character
          British Latin-1.
          There are a few other 94-character sets:
            C = 0  -> DEC Special Character and Line Drawing Set, VT100.
            C = <  -> DEC Supplemental, VT200.
            C = <  -> User Preferred Selection Set, VT300.
            C = >  -> DEC Technical, VT300.
          These are documented as 94-character sets (like USASCII)
          without NRCS:
            C = " 4  -> DEC Hebrew, VT500.
            C = " ?  -> DEC Greek, VT500.
            C = % 0  -> DEC Turkish, VT500.
            C = % 5  -> DEC Supplemental Graphics, VT300.
            C = & 4  -> DEC Cyrillic, VT500.
            C = I  -> JIS-Katakana, VT382.
            C = J  -> JIS-Roman, VT382.
          The VT520 reference manual lists a few more, but no
          documentation has been found for the mappings:
            C = % 3  -> SCS NRCS, VT500.
            C = & 5  -> DEC Russian, VT500.

ESC ) C   Designate G1 Character Set, ISO 2022, VT100.
          The same character sets apply as for ESC ( C.

ESC * C   Designate G2 Character Set, ISO 2022, VT220.
          The same character sets apply as for ESC ( C.

ESC + C   Designate G3 Character Set, ISO 2022, VT220.
          The same character sets apply as for ESC ( C.

ESC - C   Designate G1 Character Set, VT300.
          These controls apply only to 96-character sets.  Unlike the
          94-character sets, these can have different values than ASCII
          space and DEL for the mapping of 0x20 and 0x7f.  The valid
          final characters C for this control are:
            C = A  -> ISO Latin-1 Supplemental, VT300.
            C = B  -> ISO Latin-2 Supplemental, VT500.
            C = F  -> ISO Greek Supplemental, VT500.
            C = H  -> ISO Hebrew Supplemental, VT500.
            C = L  -> ISO Latin-Cyrillic, VT500.
            C = M  -> ISO Latin-5 Supplemental, VT500.

ESC . C   Designate G2 Character Set, VT300.
          The same character sets apply as for ESC - C.

ESC / C   Designate G3 Character Set, VT300.
          The same character sets apply as for ESC - C.

ESC 6     Back Index (DECBI), VT420 and up.

ESC 7     Save Cursor (DECSC), VT100.

ESC 8     Restore Cursor (DECRC), VT100.

ESC 9     Forward Index (DECFI), VT420 and up.

ESC =     Application Keypad (DECKPAM).

ESC >     Normal Keypad (DECKPNM), VT100.

ESC F     Cursor to lower left corner of screen.  This is enabled by the
          hpLowerleftBugCompat resource.

ESC c     Full Reset (RIS), VT100.

ESC l     Memory Lock (per HP terminals).  Locks memory above the
          cursor.

ESC m     Memory Unlock (per HP terminals).

ESC n     Invoke the G2 Character Set as GL (LS2).

ESC o     Invoke the G3 Character Set as GL (LS3).

ESC |     Invoke the G3 Character Set as GR (LS3R).

ESC }     Invoke the G2 Character Set as GR (LS2R).

ESC ~     Invoke the G1 Character Set as GR (LS1R), VT100.


Application Program-Command functions

APC Pt ST None.  xterm implements no APC  functions; Pt is ignored.  Pt
          need not be printable characters.


Device-Control functions

DCS Ps ; Ps | Pt ST
          User-Defined Keys (DECUDK), VT220 and up.

          The first parameter:
            Ps = 0  -> Clear all UDK definitions before starting
          (default).
            Ps = 1  -> Erase Below (default).

          The second parameter:
            Ps = 0  <- Lock the keys (default).
            Ps = 1  <- Do not lock.

          The third parameter is a ";"-separated list of strings
          denoting the key-code separated by a "/" from the hex-encoded
          key value.  The key codes correspond to the DEC function-key
          codes (e.g., F6=17).

DCS Ps ! u Pt ST
          Assigning User-Preferred Supplemental Sets (DECAUPSS), VT320,
          VT510.  XTerm ignores this in UTF-8 mode, and uses the
          preferLatin1 resource to choose the default setting.
          VT320 provides these:
            DCS 0 ! u % 5 ST  -> DEC Supplemental Graphic
            DCS 1 ! u A ST    -> ISO Latin-1 supplemental
          VT510 adds these:
            DCS 0 ! u " ? ST  -> DEC Greek
            DCS 0 ! u " 4 ST  -> DEC Hebrew
            DCS 0 ! u % 0 ST  -> DEC Turkish
            DCS 0 ! u & 4 ST  -> DEC Cyrillic
            DCS 1 ! u B ST    -> ISO Latin-2 Supplemental
            DCS 1 ! u F ST    -> ISO Greek Supplemental
            DCS 1 ! u H ST    -> ISO Hebrew Supplemental
            DCS 1 ! u M ST    -> ISO Latin-5 Supplemental
            DCS 1 ! u L ST    -> ISO Latin-Cyrillic
          VT520 accepts a few others (undocumented); xterm adds these:
            DCS 0 ! u B ST    -> United States (USASCII).
            DCS 0 ! u 0 ST    -> DEC Special Character and Line Drawing
          Set.
            DCS 0 ! u > ST    -> DEC Technical.

DCS $ q Pt ST
          Request Status String (DECRQSS), VT420 and up.
          The string following the "q" is one of the following:
            m       -> SGR
            " p     -> DECSCL
            SP q    -> DECSCUSR
            " q     -> DECSCA
            r       -> DECSTBM
            s       -> DECSLRM
            t       -> DECSLPP
            $ |     -> DECSCPP
            $ }     -> DECSASD
            $ ~     -> DECSSDT
            ) {     -> DECSTGLT (VT525 only)
            * x     -> DECSACE
            * |     -> DECSNLS
            , |     -> DECAC (VT525 only)
            , }     -> DECATC (VT525 only)
            > Pm f  -> XTQFMTKEYS (xterm)
            > Pm m  -> XTQMODKEYS (xterm)
            > Pm t  -> XTSMTITLE (xterm)
          xterm responds with DCS 1 $ r Pt ST for valid requests,
          replacing the Pt with the corresponding CSI string, or DCS 0 $
          r  ST for invalid requests.

DCS Ps $ t Pt ST
          Restore presentation status (DECRSPS), VT320 and up.  The
          control can be converted from a response from DECCIR or
          DECTABSR by changing the first "u" to a "t"
            Ps = 1  -> DECCIR
            Ps = 2  -> DECTABSR

DCS + Q Pt ST
          Request resource values (XTGETXRES), xterm.  The string
          following the "Q" is a list of names encoded in hexadecimal (2
          digits per character) separated by ; which correspond to xterm
          resource names.

          xterm responds with
          DCS 1 + R Pt ST for valid requests, adding to Pt an = , and
          the value of the corresponding xterm resource, or
          DCS 0 + R Pt ST for invalid requests.
          The strings are encoded in hexadecimal (2 digits per
          character).

          Only boolean, numeric and string resources for the VT100
          widget are supported by this query.  XTerm evaluates resources
          at startup time.  Several of xterm's state variables use
          resources to determine their initial value.  Because the
          resource variable may not reflect the current state, xterm
          provides control sequences for querying the state directly:

          o   XTQALLOWED
          o   XTQFMTKEYS
          o   XTQMODKEYS


DCS + p Pt ST
          Set Termcap/Terminfo Data (XTSETTCAP), xterm.  The string
          following the "p" is encoded in hexadecimal.  After decoding
          it, xterm will use the name to retrieve data from the terminal
          database.  If successful, that overrides the termName resource
          when handling the "tcap" keyboard configuration's function-
          and special-keys, as well as by the Request Termcap/Terminfo
          String control.


DCS + q Pt ST
          Request Termcap/Terminfo String (XTGETTCAP), xterm.  The
          string following the "q" is a list of names encoded in
          hexadecimal (2 digits per character) separated by ; which
          correspond to termcap or terminfo capability names for special
          keyboard keys.  A terminal description will include other
          capabilities, e.g., for cursor movement, which are
          intentionally not part of this interface.
          A few more terminal capabilities are recognized, which are not
          names of special keys:

          o   Co for termcap colors (or colors for terminfo colors), and

          o   TN for termcap name (or name for terminfo name).

          o   RGB for the ncurses direct-color extension.
              Only a terminfo name is provided, since termcap
              applications cannot use this information.

          These capabilities fall into two categories:

          o   Terminal capabilities which may be dynamically adjusted in
              xterm so they do not necessarily match a terminal
              description.

          o   The name of the terminal description, which an application
              can use to obtain the static set of capabilities.

          xterm responds with
          DCS 1 + r Pt ST for valid requests, adding to Pt an = , and
          the value of the corresponding string that xterm would send,
          or
          DCS 0 + r ST for invalid requests.
          The strings are encoded in hexadecimal (2 digits per
          character).  If more than one name is given, xterm replies
          with each name/value pair in the same response.  An invalid
          name (one not found in xterm's tables) ends processing of the
          list of names.


Functions using CSI , ordered by the final character(s)

CSI Ps @  Insert Ps (Blank) Character(s) (default = 1) (ICH).

CSI Ps SP @
          Shift left Ps columns(s) (default = 1) (SL), ECMA-48.

CSI Ps A  Cursor Up Ps Times (default = 1) (CUU).

CSI Ps SP A
          Shift right Ps columns(s) (default = 1) (SR), ECMA-48.

CSI Ps B  Cursor Down Ps Times (default = 1) (CUD).

CSI Ps C  Cursor Forward Ps Times (default = 1) (CUF).

CSI Ps D  Cursor Backward Ps Times (default = 1) (CUB).

CSI Ps E  Cursor Next Line Ps Times (default = 1) (CNL).

CSI Ps F  Cursor Preceding Line Ps Times (default = 1) (CPL).

CSI Ps G  Cursor Character Absolute  [column] (default = [row,1]) (CHA).

CSI Ps ; Ps H
          Cursor Position [row;column] (default = [1,1]) (CUP).

CSI Ps I  Cursor Forward Tabulation Ps tab stops (default = 1) (CHT).

CSI Ps J  Erase in Display (ED), VT100.
            Ps = 0  -> Erase Below (default).
            Ps = 1  -> Erase Above.
            Ps = 2  -> Erase All.
            Ps = 3  -> Erase Saved Lines, xterm.

CSI ? Ps J
          Erase in Display (DECSED), VT220.
            Ps = 0  -> Selective Erase Below (default).
            Ps = 1  -> Selective Erase Above.
            Ps = 2  -> Selective Erase All.
            Ps = 3  -> Selective Erase Saved Lines, xterm.

CSI Ps K  Erase in Line (EL), VT100.
            Ps = 0  -> Erase to Right (default).
            Ps = 1  -> Erase to Left.
            Ps = 2  -> Erase All.

CSI ? Ps K
          Erase in Line (DECSEL), VT220.
            Ps = 0  -> Selective Erase to Right (default).
            Ps = 1  -> Selective Erase to Left.
            Ps = 2  -> Selective Erase All.

CSI Ps L  Insert Ps Line(s) (default = 1) (IL).

CSI Ps M  Delete Ps Line(s) (default = 1) (DL).

CSI Ps P  Delete Ps Character(s) (default = 1) (DCH).

CSI # P
CSI Pm # P
          Push current dynamic- and ANSI-palette colors onto stack
          (XTPUSHCOLORS), xterm.  Parameters (integers in the range 1
          through 10, since the default 0 will push) may be used to
          store the palette into the stack without pushing.

CSI # Q
CSI Pm # Q
          Pop stack to set dynamic- and ANSI-palette colors
          (XTPOPCOLORS), xterm.  Parameters (integers in the range 1
          through 10, since the default 0 will pop) may be used to
          restore the palette from the stack without popping.

CSI # R   Report the current entry on the palette stack, and the number
          of palettes stored on the stack, using the same form as
          XTPOPCOLORS (default = 0) (XTREPORTCOLORS), xterm.

CSI Ps S  Scroll up Ps lines (default = 1) (SU), VT420, ECMA-48.

CSI # S   Report position on title-stack (XTTITLEPOS), xterm.
          Response is the same format, with parameters:
            CSI Pn; Pm # S
          where
            Pn is the current index into the title stack
            Pm is the maximum index for the title stack

CSI ? Pi ; Pa ; Pv S
          Set or request graphics attribute (XTSMGRAPHICS), xterm.  If
          configured to support either Sixel Graphics or ReGIS Graphics,
          xterm accepts a three-parameter control sequence, where Pi, Pa
          and Pv are the item, action and value:

            Pi = 1  -> item is number of color registers.
            Pi = 2  -> item is Sixel graphics geometry (in pixels).
            Pi = 3  -> item is ReGIS graphics geometry (in pixels).

            Pa = 1  -> read attribute.
            Pa = 2  -> reset to default.
            Pa = 3  -> set to value in Pv.
            Pa = 4  -> read the maximum allowed value.

            Pv is ignored by xterm except when setting (Pa == 3 ).
            Pv = n <- A single integer is used for color registers.
            Pv = width ; height <- Two integers for graphics geometry.

          xterm replies with a control sequence of the same form:

               CSI ? Pi ; Ps ; Pv S

          where Ps is the status:
            Ps = 0  <- success.
            Ps = 1  <- error in Pi.
            Ps = 2  <- error in Pa.
            Ps = 3  <- failure.

          On success, Pv represents the value read or set.

          Notes:
          o   The current implementation allows reading the graphics
              sizes, but disallows modifying those sizes because that is
              done once, using resource-values.
          o   Graphics geometry is not necessarily the same as "window
              size" (see the XTWINOPS window manipulation extensions).
              XTerm limits the maximum graphics geometry according to
              the maxGraphicSize resource.
              The maxGraphicSize resource can be either an explicit
              heightxwidth (default: 1000x1000 as of version 328) or the
              word "auto" (telling XTerm to use limits the decGraphicsID
              or decTerminalID resource to determine the limits).
          o   XTerm uses the minimum of the window size and the graphic
              size to obtain the maximum geometry.
          o   While resizing a window will always change the current
              graphics geometry, the reverse is not true.  Setting
              graphics geometry does not affect the window size.
          o   If xterm is able to support graphics (compile-time), but
              is not configured (runtime) for graphics, these responses
              will indicate a failure.  Other implementations which do
              not use the maximum graphics dimensions but are configured
              for graphics should report zeroes for the maximum geometry
              rather than a failure.

CSI Ps T  Scroll down Ps lines (default = 1) (SD), VT420.

CSI Ps ; Ps ; Ps ; Ps ; Ps T
          Initiate highlight mouse tracking (XTHIMOUSE), xterm.
          Parameters are [func;startx;starty;firstrow;lastrow].  See the
          section Mouse Tracking.

CSI > Pm T
          Reset title mode features to default value (XTRMTITLE), xterm.
          Normally, "reset" disables the feature.  It is possible to
          disable the ability to reset features by compiling a different
          default for the title modes into xterm.

          If no parameters are given, all title mode features are reset
          to the initial (compiled-in) default.

            Ps = 0  -> Do not set window/icon labels using hexadecimal.
            Ps = 1  -> Do not query window/icon labels using
          hexadecimal.
            Ps = 2  -> Do not set window/icon labels using UTF-8.
            Ps = 3  -> Do not query window/icon labels using UTF-8.

          (See discussion of Title Modes).

CSI ? 5 W Reset tab stops to start with column 9, every 8 columns
          (DECST8C), VT510.

CSI Ps X  Erase Ps Character(s) (default = 1) (ECH).

CSI Ps Z  Cursor Backward Tabulation Ps tab stops (default = 1) (CBT).

CSI Ps ^  Scroll down Ps lines (default = 1) (SD), ECMA-48.
          This was a publication error in the original ECMA-48 5th
          edition (1991) corrected in 2003.

CSI Ps `  Character Position Absolute  [column] (default = [row,1])
          (HPA).

CSI Ps a  Character Position Relative  [columns] (default = [row,col+1])
          (HPR).

CSI Ps b  Repeat the preceding graphic character Ps times (REP).

CSI Ps c  Send Device Attributes (Primary DA).
            Ps = 0  or omitted -> request attributes from terminal.  The
          response depends on the decTerminalID resource setting.
            -> CSI ? 1 ; 2 c  ("VT100 with Advanced Video Option")
            -> CSI ? 1 ; 0 c  ("VT101 with No Options")
            -> CSI ? 4 ; 6 c  ("VT132 with Advanced Video and Graphics")
            -> CSI ? 6 c  ("VT102")
            -> CSI ? 7 c  ("VT131")
            -> CSI ? 1 2 ; Ps c  ("VT125")
            -> CSI ? 6 2 ; Ps c  ("VT220")
            -> CSI ? 6 3 ; Ps c  ("VT320")
            -> CSI ? 6 4 ; Ps c  ("VT420")
            -> CSI ? 6 5 ; Ps c  ("VT510" to ("VT525")

          The VT100-style response parameters do not mean anything by
          themselves.  VT220 (and higher) parameters do, telling the
          host what features the terminal supports:
            Ps = 1  -> 132-columns.
            Ps = 2  -> Printer.
            Ps = 3  -> ReGIS graphics.
            Ps = 4  -> Sixel graphics.
            Ps = 6  -> Selective erase.
            Ps = 8  -> User-defined keys.
            Ps = 9  -> National Replacement Character sets.
            Ps = 1 5  -> Technical characters.
            Ps = 1 6  -> Locator port.
            Ps = 1 7  -> Terminal state interrogation.
            Ps = 1 8  -> User windows.
            Ps = 2 1  -> Horizontal scrolling.
            Ps = 2 2  -> ANSI color, e.g., VT525.
            Ps = 2 8  -> Rectangular editing.
            Ps = 2 9  -> ANSI text locator (i.e., DEC Locator mode).

          XTerm supports part of the User windows feature, providing a
          single page (which corresponds to its visible window).  Rather
          than resizing the font to change the number of lines/columns
          in a fixed-size display, xterm uses the window extension
          controls (DECSNLS, DECSCPP, DECSLPP) to adjust its visible
          window's size.  The "cursor coupling" controls (DECHCCM,
          DECPCCM, DECVCCM) are ignored.

CSI = Ps c
          Send Device Attributes (Tertiary DA).
            Ps = 0  -> report Terminal Unit ID (default), VT400.  XTerm
          uses zeros for the site code and serial number in its DECRPTUI
          response.

CSI > Ps c
          Send Device Attributes (Secondary DA).
            Ps = 0  or omitted -> request the terminal's identification
          code.  The response depends on the decTerminalID resource
          setting.  It should apply only to VT220 and up, but xterm
          extends this to VT100.
            -> CSI  > Pp ; Pv ; Pc c
          where Pp denotes the terminal type
            Pp = 0  -> "VT100".
            Pp = 1  -> "VT220".
            Pp = 2  -> "VT240" or "VT241".
            Pp = 1 8  -> "VT330".
            Pp = 1 9  -> "VT340".
            Pp = 2 4  -> "VT320".
            Pp = 3 2  -> "VT382".
            Pp = 4 1  -> "VT420".
            Pp = 6 1  -> "VT510".
            Pp = 6 4  -> "VT520".
            Pp = 6 5  -> "VT525".

          and Pv is the firmware version (for xterm, this was originally
          the XFree86 patch number, starting with 95).  In a DEC
          terminal, Pc indicates the ROM cartridge registration number
          and is always zero.

CSI Ps d  Line Position Absolute  [row] (default = [1,column]) (VPA).

CSI Ps e  Line Position Relative  [rows] (default = [row+1,column])
          (VPR).

CSI Ps ; Ps f
          Horizontal and Vertical Position [row;column] (default =
          [1,1]) (HVP).

CSI > Pp ; Pv f
CSI > Pp f
          Set/reset key format options (XTFMTKEYS), xterm.  Set or reset
          resource-values used by xterm to decide how to format escape
          sequences holding information about the modifiers pressed with
          a given key.

          The first parameter Pp identifies the resource to set/reset.
          The second parameter Pv is the value to assign to the
          resource.

          If the second parameter is omitted, the resource is reset to
          its initial value.  Value 5  is reserved for input via the
          string action.

            Pp = 0  -> formatKeyboard.
            Pp = 1  -> formatCursorKeys.
            Pp = 2  -> formatFunctionKeys.
            Pp = 3  -> formatKeypadKeys.
            Pp = 4  -> formatOtherKeys.
            Pp = 6  -> formatModifierKeys.
            Pp = 7  -> formatSpecialKeys.

          If no parameters are given, all resources are reset to their
          initial values.  See Alt and Meta Keys for more details on the
          formatOtherKeys feature.

CSI Ps g  Tab Clear (TBC).  ECMA-48 defines additional codes, but the
          VT100 user manual notes that it ignores other codes.  DEC's
          later terminals (and xterm) do the same, for compatibility.
            Ps = 0  -> Clear Current Column (default).
            Ps = 3  -> Clear All.

CSI ? Pp g
          Query key modifier options (XTQFMTKEYS), xterm.

          The parameter Pp identifies the resource to query.

            Pp = 0  -> formatKeyboard.
            Pp = 1  -> formatCursorKeys.
            Pp = 2  -> formatFunctionKeys.
            Pp = 3  -> formatKeypadKeys.
            Pp = 4  -> formatOtherKeys.
            Pp = 6  -> formatModifierKeys.
            Pp = 7  -> formatSpecialKeys.

          XTerm's response can be used to restore this state, because it
          is formatted as an XTFMTKEYS control, i.e.,

            CSI > Pp f

          where

            Pp = 0  -> formatKeyboard.
            Pp = 1  -> formatCursorKeys.
            Pp = 2  -> formatFunctionKeys.
            Pp = 3  -> formatKeypadKeys.
            Pp = 4  -> formatOtherKeys.
            Pp = 6  -> formatModifierKeys.
            Pp = 7  -> formatSpecialKeys.

CSI Pm h  Set Mode (SM).
            Ps = 2  -> Keyboard Action Mode (KAM).
            Ps = 4  -> Insert Mode (IRM).
            Ps = 1 2  -> Send/receive (SRM).
            Ps = 2 0  -> Automatic Newline (LNM).

CSI ? Pm h
          DEC Private Mode Set (DECSET).
            Ps = 1  -> Application Cursor Keys (DECCKM), VT100.
            Ps = 2  -> Designate USASCII for character sets G0-G3
          (DECANM), VT100, and set VT100 mode.
            Ps = 3  -> 132 Column Mode (DECCOLM), VT100.
            Ps = 4  -> Smooth (Slow) Scroll (DECSCLM), VT100.
            Ps = 5  -> Reverse Video (DECSCNM), VT100.
            Ps = 6  -> Origin Mode (DECOM), VT100.
            Ps = 7  -> Auto-Wrap Mode (DECAWM), VT100.
            Ps = 8  -> Auto-Repeat Keys (DECARM), VT100.
            Ps = 9  -> Send Mouse X & Y on button press.  See the
          section Mouse Tracking.  This is the X10 xterm mouse protocol.
            Ps = 1 0  -> Show toolbar (rxvt).
            Ps = 1 2  -> Start blinking cursor (AT&T 610).
            Ps = 1 3  -> Start blinking cursor (set only via resource or
          menu).
            Ps = 1 4  -> Enable XOR of blinking cursor control sequence
          and menu.
            Ps = 1 8  -> Print Form Feed (DECPFF), VT220.
            Ps = 1 9  -> Set print extent to full screen (DECPEX),
          VT220.
            Ps = 2 5  -> Show cursor (DECTCEM), VT220.
            Ps = 3 0  -> Show scrollbar (rxvt).
            Ps = 3 5  -> Enable font-shifting functions (rxvt).
            Ps = 3 8  -> Enter Tektronix mode (DECTEK), VT240, xterm.
            Ps = 4 0  -> Allow 80 -> 132 mode, xterm.
            Ps = 4 1  -> more(1) fix (see curses resource).
            Ps = 4 2  -> Enable National Replacement Character sets
          (DECNRCM), VT220.
            Ps = 4 3  -> Enable Graphic Expanded Print Mode (DECGEPM),
          VT340.
            Ps = 4 4  -> Turn on margin bell, xterm.
            Ps = 4 4  -> Enable Graphic Print Color Mode (DECGPCM),
          VT340.
            Ps = 4 5  -> Reverse-wraparound mode (XTREVWRAP), xterm.
            Ps = 4 5  -> Enable Graphic Print Color Syntax (DECGPCS),
          VT340.
            Ps = 4 6  -> Start logging (XTLOGGING), xterm.  This is
          normally disabled by a compile-time option.
            Ps = 4 6  -> Graphic Print Background Mode, VT340.
            Ps = 4 7  -> Use Alternate Screen Buffer, xterm.  This may
          be disabled by the titeInhibit resource.
            Ps = 4 7  -> Enable Graphic Rotated Print Mode (DECGRPM),
          VT340.
            Ps = 6 6  -> Application keypad mode (DECNKM), VT320.
            Ps = 6 7  -> Backarrow key sends backspace (DECBKM), VT340,
          VT420.  This sets the backarrowKey resource to "true".
            Ps = 6 9  -> Enable left and right margin mode (DECLRMM),
          VT420 and up.
            Ps = 8 0  -> Enable Sixel Display Mode (DECSDM), VT330,
          VT340, VT382.
            Ps = 9 5  -> Do not clear screen when DECCOLM is set/reset
          (DECNCSM), VT510 and up.
            Ps = 1 0 0 0  -> Send Mouse X & Y on button press and
          release.  See the section Mouse Tracking.  This is the X11
          xterm mouse protocol.
            Ps = 1 0 0 1  -> Use Hilite Mouse Tracking, xterm.
            Ps = 1 0 0 2  -> Use Cell Motion Mouse Tracking, xterm.  See
          the section Button-event tracking.
            Ps = 1 0 0 3  -> Use All Motion Mouse Tracking, xterm.  See
          the section Any-event tracking.
            Ps = 1 0 0 4  -> Send FocusIn/FocusOut events, xterm.
            Ps = 1 0 0 5  -> Enable UTF-8 Mouse Mode, xterm.
            Ps = 1 0 0 6  -> Enable SGR Mouse Mode, xterm.
            Ps = 1 0 0 7  -> Enable Alternate Scroll Mode, xterm.  This
          corresponds to the alternateScroll resource.
            Ps = 1 0 1 0  -> Scroll to bottom on tty output (rxvt).
          This sets the scrollTtyOutput resource to "true".
            Ps = 1 0 1 1  -> Scroll to bottom on key press (rxvt).  This
          sets the scrollKey resource to "true".
            Ps = 1 0 1 4  -> Enable fastScroll resource, xterm.
            Ps = 1 0 1 5  -> Enable urxvt Mouse Mode.
            Ps = 1 0 1 6  -> Enable SGR Mouse PixelMode, xterm.
            Ps = 1 0 2 0  -> utf8 resource setting, xterm.
            Ps = 1 0 2 1  -> cjkWidth resource setting, xterm.
            Ps = 1 0 2 2  -> emojiWidth resource setting, xterm.
            Ps = 1 0 2 3  -> privateWidth resource setting, xterm.
            Ps = 1 0 3 4  -> Interpret "meta" key, xterm.  This sets the
          eighth bit of keyboard input (and enables the eightBitInput
          resource).
            Ps = 1 0 3 5  -> Enable special modifiers for Alt and
          NumLock keys, xterm.  This enables the numLock resource.
            Ps = 1 0 3 6  -> Send ESC   when Meta modifies a key, xterm.
          This enables the metaSendsEscape resource.
            Ps = 1 0 3 7  -> Send DEL from the editing-keypad Delete
          key, xterm.
            Ps = 1 0 3 9  -> Send ESC  when Alt modifies a key, xterm.
          This enables the altSendsEscape resource, xterm.
            Ps = 1 0 4 0  -> Keep selection even if not highlighted,
          xterm.  This enables the keepSelection resource.
            Ps = 1 0 4 1  -> Use the CLIPBOARD selection, xterm.  This
          enables the selectToClipboard resource.
            Ps = 1 0 4 2  -> Enable Urgency window manager hint when
          Control-G is received, xterm.  This enables the bellIsUrgent
          resource.
            Ps = 1 0 4 3  -> Enable raising of the window when Control-G
          is received, xterm.  This enables the popOnBell resource.
            Ps = 1 0 4 4  -> Reuse the most recent data copied to
          CLIPBOARD, xterm.  This enables the keepClipboard resource.
            Ps = 1 0 4 5  -> Extended Reverse-wraparound mode
          (XTREVWRAP2), xterm.
            Ps = 1 0 4 6  -> Enable switching to/from Alternate Screen
          Buffer, xterm.  This works for terminfo-based systems,
          updating the titeInhibit resource.
            Ps = 1 0 4 7  -> Use Alternate Screen Buffer, xterm.  This
          may be disabled by the titeInhibit resource.
            Ps = 1 0 4 8  -> Save cursor as in DECSC, xterm.  This may
          be disabled by the titeInhibit resource.
            Ps = 1 0 4 9  -> Save cursor as in DECSC, xterm.  After
          saving the cursor, switch to the Alternate Screen Buffer,
          clearing it first.  This may be disabled by the titeInhibit
          resource.  This control combines the effects of the 1 0 4 7
          and 1 0 4 8  modes.  Use this with terminfo-based applications
          rather than the 4 7  mode.
            Ps = 1 0 5 0  -> Set terminfo/termcap function-key mode,
          xterm.
            Ps = 1 0 5 1  -> Set Sun function-key mode, xterm.
            Ps = 1 0 5 2  -> Set HP function-key mode, xterm.
            Ps = 1 0 5 3  -> Set SCO function-key mode, xterm.
            Ps = 1 0 6 0  -> Set legacy keyboard emulation, i.e, X11R6,
          xterm.
            Ps = 1 0 6 1  -> Set VT220 keyboard emulation, xterm.
            Ps = 2 0 0 1  -> Enable readline mouse button-1, xterm.
            Ps = 2 0 0 2  -> Enable readline mouse button-2, xterm.
            Ps = 2 0 0 3  -> Enable readline mouse button-3, xterm.
            Ps = 2 0 0 4  -> Set bracketed paste mode, xterm.
            Ps = 2 0 0 5  -> Enable readline character-quoting, xterm.
            Ps = 2 0 0 6  -> Enable readline newline pasting, xterm.

CSI Ps i  Media Copy (MC).
            Ps = 0  -> Print screen (default).
            Ps = 4  -> Turn off printer controller mode.
            Ps = 5  -> Turn on printer controller mode.
            Ps = 1 0  -> HTML screen dump, xterm.
            Ps = 1 1  -> SVG screen dump, xterm.

CSI ? Ps i
          Media Copy (MC), DEC-specific.
            Ps = 1  -> Print line containing cursor.
            Ps = 4  -> Turn off autoprint mode.
            Ps = 5  -> Turn on autoprint mode.
            Ps = 1 0  -> Print composed display, ignores DECPEX.
            Ps = 1 1  -> Print all pages.

CSI Pm l  Reset Mode (RM).
            Ps = 2  -> Keyboard Action Mode (KAM).
            Ps = 4  -> Replace Mode (IRM).
            Ps = 1 2  -> Send/receive (SRM).
            Ps = 2 0  -> Normal Linefeed (LNM).

CSI ? Pm l
          DEC Private Mode Reset (DECRST).
            Ps = 1  -> Normal Cursor Keys (DECCKM), VT100.
            Ps = 2  -> Designate VT52 mode (DECANM), VT100.
            Ps = 3  -> 80 Column Mode (DECCOLM), VT100.
            Ps = 4  -> Jump (Fast) Scroll (DECSCLM), VT100.
            Ps = 5  -> Normal Video (DECSCNM), VT100.
            Ps = 6  -> Normal Cursor Mode (DECOM), VT100.
            Ps = 7  -> No Auto-Wrap Mode (DECAWM), VT100.
            Ps = 8  -> No Auto-Repeat Keys (DECARM), VT100.
            Ps = 9  -> Don't send Mouse X & Y on button press, xterm.
            Ps = 1 0  -> Hide toolbar (rxvt).
            Ps = 1 2  -> Stop blinking cursor (AT&T 610).
            Ps = 1 3  -> Disable blinking cursor (reset only via
          resource or menu).
            Ps = 1 4  -> Disable XOR of blinking cursor control sequence
          and menu.
            Ps = 1 8  -> Don't Print Form Feed (DECPFF), VT220.
            Ps = 1 9  -> Limit print to scrolling region (DECPEX),
          VT220.
            Ps = 2 5  -> Hide cursor (DECTCEM), VT220.
            Ps = 3 0  -> Don't show scrollbar (rxvt).
            Ps = 3 5  -> Disable font-shifting functions (rxvt).
            Ps = 4 0  -> Disallow 80 -> 132 mode, xterm.
            Ps = 4 1  -> No more(1) fix (see curses resource).
            Ps = 4 2  -> Disable National Replacement Character sets
          (DECNRCM), VT220.
            Ps = 4 3  -> Disable Graphic Expanded Print Mode (DECGEPM),
          VT340.
            Ps = 4 4  -> Turn off margin bell, xterm.
            Ps = 4 4  -> Disable Graphic Print Color Mode (DECGPCM),
          VT340.
            Ps = 4 5  -> No Reverse-wraparound mode (XTREVWRAP), xterm.
            Ps = 4 5  -> Disable Graphic Print Color Syntax (DECGPCS),
          VT340.
            Ps = 4 6  -> Stop logging (XTLOGGING), xterm.  This is
          normally disabled by a compile-time option.
            Ps = 4 7  -> Use Normal Screen Buffer, xterm.
            Ps = 4 7  -> Disable Graphic Rotated Print Mode (DECGRPM),
          VT340.
            Ps = 6 6  -> Numeric keypad mode (DECNKM), VT320.
            Ps = 6 7  -> Backarrow key sends delete (DECBKM), VT340,
          VT420.  This sets the backarrowKey resource to "false".
            Ps = 6 9  -> Disable left and right margin mode (DECLRMM),
          VT420 and up.
            Ps = 8 0  -> Disable Sixel Display Mode (DECSDM), VT330,
          VT340, VT382.  Turns on "Sixel Scrolling".  See the section
          Sixel Graphics and mode 8 4 5 2 .
            Ps = 9 5  -> Clear screen when DECCOLM is set/reset
          (DECNCSM), VT510 and up.
            Ps = 1 0 0 0  -> Don't send Mouse X & Y on button press and
          release.  See the section Mouse Tracking.
            Ps = 1 0 0 1  -> Don't use Hilite Mouse Tracking, xterm.
            Ps = 1 0 0 2  -> Don't use Cell Motion Mouse Tracking,
          xterm.  See the section Button-event tracking.
            Ps = 1 0 0 3  -> Don't use All Motion Mouse Tracking, xterm.
          See the section Any-event tracking.
            Ps = 1 0 0 4  -> Don't send FocusIn/FocusOut events, xterm.
            Ps = 1 0 0 5  -> Disable UTF-8 Mouse Mode, xterm.
            Ps = 1 0 0 6  -> Disable SGR Mouse Mode, xterm.
            Ps = 1 0 0 7  -> Disable Alternate Scroll Mode, xterm.  This
          corresponds to the alternateScroll resource.
            Ps = 1 0 1 0  -> Don't scroll to bottom on tty output
          (rxvt).  This sets the scrollTtyOutput resource to "false".
            Ps = 1 0 1 1  -> Don't scroll to bottom on key press (rxvt).
          This sets the scrollKey resource to "false".
            Ps = 1 0 1 4  -> Disable fastScroll resource, xterm.
            Ps = 1 0 1 5  -> Disable urxvt Mouse Mode.
            Ps = 1 0 1 6  -> Disable SGR Mouse Pixel-Mode, xterm.
            Ps = 1 0 3 4  -> Don't interpret "meta" key, xterm.  This
          disables the eightBitInput resource.
            Ps = 1 0 3 5  -> Disable special modifiers for Alt and
          NumLock keys, xterm.  This disables the numLock resource.
            Ps = 1 0 3 6  -> Don't send ESC  when Meta modifies a key,
          xterm.  This disables the metaSendsEscape resource.
            Ps = 1 0 3 7  -> Send VT220 Remove from the editing-keypad
          Delete key, xterm.
            Ps = 1 0 3 9  -> Don't send ESC when Alt modifies a key,
          xterm.  This disables the altSendsEscape resource.
            Ps = 1 0 4 0  -> Do not keep selection when not highlighted,
          xterm.  This disables the keepSelection resource.
            Ps = 1 0 4 1  -> Use the PRIMARY selection, xterm.  This
          disables the selectToClipboard resource.
            Ps = 1 0 4 2  -> Disable Urgency window manager hint when
          Control-G is received, xterm.  This disables the bellIsUrgent
          resource.
            Ps = 1 0 4 3  -> Disable raising of the window when Control-
          G is received, xterm.  This disables the popOnBell resource.
            Ps = 1 0 4 5  -> No Extended Reverse-wraparound mode
          (XTREVWRAP2), xterm.
            Ps = 1 0 4 6  -> Disable switching to/from Alternate Screen
          Buffer, xterm.  This works for terminfo-based systems,
          updating the titeInhibit resource.  If currently using the
          Alternate Screen Buffer, xterm switches to the Normal Screen
          Buffer.
            Ps = 1 0 4 7  -> Use Normal Screen Buffer, xterm.  Clear the
          screen first if in the Alternate Screen Buffer.  This may be
          disabled by the titeInhibit resource.
            Ps = 1 0 4 8  -> Restore cursor as in DECRC, xterm.  This
          may be disabled by the titeInhibit resource.
            Ps = 1 0 4 9  -> Use Normal Screen Buffer and restore cursor
          as in DECRC, xterm.  This may be disabled by the titeInhibit
          resource.  This combines the effects of the 1 0 4 7  and 1 0 4
          8  modes.  Use this with terminfo-based applications rather
          than the 4 7  mode.
            Ps = 1 0 5 0  -> Reset terminfo/termcap function-key mode,
          xterm.
            Ps = 1 0 5 1  -> Reset Sun function-key mode, xterm.
            Ps = 1 0 5 2  -> Reset HP function-key mode, xterm.
            Ps = 1 0 5 3  -> Reset SCO function-key mode, xterm.
            Ps = 1 0 6 0  -> Reset legacy keyboard emulation, i.e,
          X11R6, xterm.
            Ps = 1 0 6 1  -> Reset keyboard emulation to Sun/PC style,
          xterm.
            Ps = 2 0 0 1  -> Disable readline mouse button-1, xterm.
            Ps = 2 0 0 2  -> Disable readline mouse button-2, xterm.
            Ps = 2 0 0 3  -> Disable readline mouse button-3, xterm.
            Ps = 2 0 0 4  -> Reset bracketed paste mode, xterm.
            Ps = 2 0 0 5  -> Disable readline character-quoting, xterm.
            Ps = 2 0 0 6  -> Disable readline newline pasting, xterm.

CSI Pm m  Character Attributes (SGR).
            Ps = 0  -> Normal (default), VT100.
            Ps = 1  -> Bold, VT100.
            Ps = 2  -> Faint, decreased intensity, ECMA-48 2nd.
            Ps = 3  -> Italicized, ECMA-48 2nd.
            Ps = 4  -> Underlined, VT100.
            Ps = 5  -> Blink, VT100.
          This appears as Bold in X11R6 xterm.
            Ps = 7  -> Inverse, VT100.
            Ps = 8  -> Invisible, i.e., hidden, ECMA-48 2nd, VT300.
            Ps = 9  -> Crossed-out characters, ECMA-48 3rd.
            Ps = 2 1  -> Doubly-underlined, ECMA-48 3rd.
            Ps = 2 2  -> Normal (neither bold nor faint), ECMA-48 3rd.
            Ps = 2 3  -> Not italicized, ECMA-48 3rd.
            Ps = 2 4  -> Not underlined, ECMA-48 3rd.
            Ps = 2 5  -> Steady (not blinking), ECMA-48 3rd.
            Ps = 2 7  -> Positive (not inverse), ECMA-48 3rd.
            Ps = 2 8  -> Visible, i.e., not hidden, ECMA-48 3rd, VT300.
            Ps = 2 9  -> Not crossed-out, ECMA-48 3rd.
            Ps = 3 0  -> Set foreground color to Black.
            Ps = 3 1  -> Set foreground color to Red.
            Ps = 3 2  -> Set foreground color to Green.
            Ps = 3 3  -> Set foreground color to Yellow.
            Ps = 3 4  -> Set foreground color to Blue.
            Ps = 3 5  -> Set foreground color to Magenta.
            Ps = 3 6  -> Set foreground color to Cyan.
            Ps = 3 7  -> Set foreground color to White.
            Ps = 3 9  -> Set foreground color to default, ECMA-48 3rd.
            Ps = 4 0  -> Set background color to Black.
            Ps = 4 1  -> Set background color to Red.
            Ps = 4 2  -> Set background color to Green.
            Ps = 4 3  -> Set background color to Yellow.
            Ps = 4 4  -> Set background color to Blue.
            Ps = 4 5  -> Set background color to Magenta.
            Ps = 4 6  -> Set background color to Cyan.
            Ps = 4 7  -> Set background color to White.
            Ps = 4 9  -> Set background color to default, ECMA-48 3rd.

          Some of the above note the edition of ECMA-48 which first
          describes a feature.  In its successive editions from 1979 to
          1991 (2nd 1979, 3rd 1984, 4th 1986, and 5th 1991), ECMA-48
          listed codes through 6 5 (skipping several toward the end of
          the range).  Most of the ECMA-48 codes not implemented in
          xterm were never implemented in a hardware terminal.  Several
          (such as 3 9  and 4 9 ) are either noted in ECMA-48 as
          implementation defined, or described in vague terms.

          The successive editions of ECMA-48 give little attention to
          changes from one edition to the next, except to comment on
          features which have become obsolete.  ECMA-48 1st (1976) is
          unavailable; there is no reliable source of information which
          states whether "ANSI" color was defined in that edition, or
          later (1979).  The VT100 (1978) implemented the most commonly
          used non-color video attributes which are given in the 2nd
          edition.

          While 8-color support is described in ECMA-48 2nd edition, the
          VT500 series (introduced in 1993) were the first DEC terminals
          implementing "ANSI" color.  The DEC terminal's use of color is
          known to differ from xterm; useful documentation on this
          series became available too late to influence xterm.

          If 16-color support is compiled, the following aixterm
          controls apply.  Assume that xterm's resources are set so that
          the ISO color codes are the first 8 of a set of 16.  Then the
          aixterm colors are the bright versions of the ISO colors:

            Ps = 9 0  -> Set foreground color to Black.
            Ps = 9 1  -> Set foreground color to Red.
            Ps = 9 2  -> Set foreground color to Green.
            Ps = 9 3  -> Set foreground color to Yellow.
            Ps = 9 4  -> Set foreground color to Blue.
            Ps = 9 5  -> Set foreground color to Magenta.
            Ps = 9 6  -> Set foreground color to Cyan.
            Ps = 9 7  -> Set foreground color to White.
            Ps = 1 0 0  -> Set background color to Black.
            Ps = 1 0 1  -> Set background color to Red.
            Ps = 1 0 2  -> Set background color to Green.
            Ps = 1 0 3  -> Set background color to Yellow.
            Ps = 1 0 4  -> Set background color to Blue.
            Ps = 1 0 5  -> Set background color to Magenta.
            Ps = 1 0 6  -> Set background color to Cyan.
            Ps = 1 0 7  -> Set background color to White.

          If xterm is compiled with the 16-color support disabled, it
          supports the following, from rxvt:
            Ps = 1 0 0  -> Set foreground and background color to
          default.

          XTerm maintains a color palette whose entries are identified
          by an index beginning with zero.  If 88- or 256-color support
          is compiled, the following apply:
          o   All parameters are decimal integers.
          o   RGB values range from zero (0) to 255.
          o   The 88- and 256-color support uses subparameters described
              in ISO-8613-6 for indexed color.  ISO-8613-6 also mentions
              direct color, using a similar scheme.  xterm supports
              that, too.
          o   xterm allows either colons (standard) or semicolons
              (legacy) to separate the subparameters (but after the
              first colon, colons must be used).

          The indexed- and direct-color features are summarized in the
          FAQ, which explains why semicolon is accepted as a
          subparameter delimiter:

            Can I set a color by its number?

          These ISO-8613-6 controls (marked in ECMA-48 5th edition as
          "reserved for future standardization") are supported by xterm:
            Ps = 3 8 : 2 : Pi : Pr : Pg : Pb -> Set foreground color
          using RGB values.  If xterm is not compiled with direct-color
          support, it uses the closest match in its palette for the
          given RGB Pr/Pg/Pb.  The color space identifier Pi is ignored.
            Ps = 3 8 : 5 : Ps -> Set foreground color to Ps, using
          indexed color.
            Ps = 4 8 : 2 : Pi : Pr : Pg : Pb -> Set background color
          using RGB values.  If xterm is not compiled with direct-color
          support, it uses the closest match in its palette for the
          given RGB Pr/Pg/Pb.  The color space identifier Pi is ignored.
            Ps = 4 8 : 5 : Ps -> Set background color to Ps, using
          indexed color.

          This variation on ISO-8613-6 is supported for compatibility
          with KDE konsole:
            Ps = 3 8 ; 2 ; Pr ; Pg ; Pb -> Set foreground color using
          RGB values.  If xterm is not compiled with direct-color
          support, it uses the closest match in its palette for the
          given RGB Pr/Pg/Pb.
            Ps = 4 8 ; 2 ; Pr ; Pg ; Pb -> Set background color using
          RGB values.  If xterm is not compiled with direct-color
          support, it uses the closest match in its palette for the
          given RGB Pr/Pg/Pb.

          In each case, if xterm is compiled with direct-color support,
          and the resource directColor is true, then rather than
          choosing the closest match, xterm asks the X server to
          directly render a given color.

CSI > Pp ; Pv m
CSI > Pp m
          Set/reset key modifier options (XTMODKEYS), xterm.  Set or
          reset resource-values used by xterm to decide whether to
          construct escape sequences holding information about the
          modifiers pressed with a given key.

          The first parameter Pp identifies the resource to set/reset.
          The second parameter Pv is the value to assign to the
          resource.

          If the second parameter is omitted, the resource is reset to
          its initial value.  Value 5  is reserved for input via the
          string action.

            Pp = 0  -> modifyKeyboard.
            Pp = 1  -> modifyCursorKeys.
            Pp = 2  -> modifyFunctionKeys.
            Pp = 3  -> modifyKeypadKeys.
            Pp = 4  -> modifyOtherKeys.
            Pp = 6  -> modifyModifierKeys.
            Pp = 7  -> modifySpecialKeys.

          If no parameters are given, all resources are reset to their
          initial values.  See Alt and Meta Keys for more details on the
          modifyOtherKeys feature.

CSI ? Pp m
          Query key modifier options (XTQMODKEYS), xterm.

          The parameter Pp identifies the resource to query.

            Pp = 0  -> modifyKeyboard.
            Pp = 1  -> modifyCursorKeys.
            Pp = 2  -> modifyFunctionKeys.
            Pp = 3  -> modifyKeypadKeys.
            Pp = 4  -> modifyOtherKeys.
            Pp = 6  -> modifyModifierKeys.
            Pp = 7  -> modifySpecialKeys.

          XTerm's response can be used to restore this state, because it
          is formatted as an XTMODKEYS control, i.e.,

            CSI > Pp m

          where

            Pp = 0  -> modifyKeyboard.
            Pp = 1  -> modifyCursorKeys.
            Pp = 2  -> modifyFunctionKeys.
            Pp = 3  -> modifyKeypadKeys.
            Pp = 4  -> modifyOtherKeys.
            Pp = 6  -> modifyModifierKeys.
            Pp = 7  -> modifySpecialKeys.

CSI Ps n  Device Status Report (DSR).
            Ps = 5  -> Status Report.
          Result ("OK") is CSI 0 n
            Ps = 6  -> Report Cursor Position (CPR) [row;column].
          Result is CSI r ; c R

          Note: it is possible for this sequence to be sent by a
          function key.  For example, with the default keyboard
          configuration the shifted F3 key may send (with shift-,
          control-, alt-modifiers)

            CSI 1 ; 2  R , or
            CSI 1 ; 5  R , or
            CSI 1 ; 6  R , etc.

          The second parameter encodes the modifiers; values range from
          2 to 16.  See the section PC-Style Function Keys for the
          codes.  The modifyFunctionKeys and modifyKeyboard resources
          can change the form of the string sent from the modified F3
          key.

CSI > Ps n
          Disable key modifier options, xterm.  These modifiers may be
          enabled via the CSI > Pm m sequence.  This control sequence
          corresponds to a resource value of "-1", which cannot be set
          with the other sequence.

          The parameter identifies the resource to be disabled:

            Ps = 0  -> modifyKeyboard.
            Ps = 1  -> modifyCursorKeys.
            Ps = 2  -> modifyFunctionKeys.
            Ps = 3  -> modifyKeypadKeys.
            Ps = 4  -> modifyOtherKeys.
            Ps = 6  -> modifyModifierKeys.
            Ps = 7  -> modifySpecialKeys.

          If the parameter is omitted, modifyFunctionKeys is disabled.
          When modifyFunctionKeys is disabled, xterm uses the modifier
          keys to make an extended sequence of function keys rather than
          adding a parameter to each function key to denote the
          modifiers.

CSI ? Ps n
          Device Status Report (DSR, DEC-specific).
            Ps = 6  -> Report Cursor Position (DECXCPR).  The response
          [row;column] is returned as
          CSI ? r ; c R
          (assumes the default page, i.e., "1").
            Ps = 1 5  -> Report Printer status.  The response is
          CSI ? 1 0 n  (ready).  or
          CSI ? 1 1 n  (not ready).
            Ps = 2 5  -> Report UDK status.  The response is
          CSI ? 2 0 n  (unlocked)
          or
          CSI ? 2 1 n  (locked).
            Ps = 2 6  -> Report Keyboard status.  The response is
          CSI ? 2 7 ; 1 ; 0 ; 0 n  (North American).

          The last two parameters apply to VT300 & up (keyboard ready)
          and VT400 & up (LK01) respectively.

            Ps = 5 5  -> Report Locator status.  The response is CSI ? 5
          0 n  Locator available, if compiled-in, or CSI ? 5 3 n  No
          Locator, if not.
            Ps = 5 6  -> Report Locator type.  The response is CSI ? 5 7
          ; 1 n  Mouse, if compiled-in, or CSI ? 5 7 ; 0 n  Cannot
          identify, if not.
            Ps = 6 2  -> Report macro space (DECMSR).  The response is
          CSI Pn *  { .
            Ps = 6 3  -> Report memory checksum (DECCKSR), VT420 and up.
          The response is DCS Pt ! ~ x x x x ST .
              Pt is the request id (from an optional parameter to the
          request).
              The x's are hexadecimal digits 0-9 and A-F.
            Ps = 7 5  -> Report data integrity.  The response is CSI ? 7
          0 n  (ready, no errors).
            Ps = 8 5  -> Report multi-session configuration.  The
          response is CSI ? 8 3 n  (not configured for multiple-session
          operation).

CSI > Ps p
          Set resource value pointerMode (XTSMPOINTER), xterm.  This is
          used by xterm to decide whether to hide the pointer cursor as
          the user types.

          Valid values for the parameter:
            Ps = 0  -> never hide the pointer.
            Ps = 1  -> hide if the mouse tracking mode is not enabled.
            Ps = 2  -> always hide the pointer, except when leaving the
          window.
            Ps = 3  -> always hide the pointer, even if leaving/entering
          the window.

          If no parameter is given, xterm uses the default, which is 1 .

CSI ! p   Soft terminal reset (DECSTR), VT220 and up.

CSI Pl ; Pc " p
          Set conformance level (DECSCL), VT220 and up.

          The first parameter selects the conformance level.  Valid
          values are:
            Pl = 6 1  -> level 1, e.g., VT100.
            Pl = 6 2  -> level 2, e.g., VT200.
            Pl = 6 3  -> level 3, e.g., VT300.
            Pl = 6 4  -> level 4, e.g., VT400.
            Pl = 6 5  -> level 5, e.g., VT500.

          The second parameter selects the C1 control transmission mode.
          This is an optional parameter, ignored in conformance level 1.
          Valid values are:
            Pc = 0  -> 8-bit controls.
            Pc = 1  -> 7-bit controls (DEC factory default).
            Pc = 2  -> 8-bit controls.

          The 7-bit and 8-bit control modes can also be set by S7C1T and
          S8C1T, but DECSCL is preferred.

CSI Ps $ p
          Request ANSI mode (DECRQM).  For VT300 and up, reply DECRPM is
            CSI Ps ; Pm $ y
          where Ps is the mode number as in SM/RM, and Pm is the mode
          value:
            0 - not recognized
            1 - set
            2 - reset
            3 - permanently set
            4 - permanently reset

CSI ? Ps $ p
          Request DEC private mode (DECRQM).  For VT300 and up, reply
          DECRPM is
            CSI ? Ps ; Pm $ y
          where Ps is the mode number as in DECSET/DECRST, Pm is the
          mode value as in the ANSI DECRQM.
          A few private modes are read-only, provided only for reporting
          their values using this control sequence.
          o   1 3  and 1 4  correspond to the resources cursorBlink and
              cursorBlinkXOR.
          o   1 0 2 0  to 1 0 2 3  correspond to the resources utf8,
              cjkWidth, emojiWidth, and privateWidth respectively.
CSI # p
CSI Pm # p
          Push video attributes onto stack (XTPUSHSGR), xterm.  This is
          an alias for CSI # { , used to work around language
          limitations of C#.

CSI > Ps q
            Ps = 0  -> Report xterm name and version (XTVERSION).
          The response is a DSR sequence identifying the version:
            DCS > | text ST

CSI Ps q  Load LEDs (DECLL), VT100.
            Ps = 0  -> Clear all LEDS (default).
            Ps = 1  -> Light Num Lock.
            Ps = 2  -> Light Caps Lock.
            Ps = 3  -> Light Scroll Lock.
            Ps = 2 1  -> Extinguish Num Lock.
            Ps = 2 2  -> Extinguish Caps Lock.
            Ps = 2 3  -> Extinguish Scroll Lock.

CSI Ps SP q
          Set cursor style (DECSCUSR), VT520.
            Ps = 0  -> blinking block.
            Ps = 1  -> blinking block (default).
            Ps = 2  -> steady block.
            Ps = 3  -> blinking underline.
            Ps = 4  -> steady underline.
            Ps = 5  -> blinking bar, xterm.
            Ps = 6  -> steady bar, xterm.

CSI Ps " q
          Select character protection attribute (DECSCA), VT220.  Valid
          values for the parameter:
            Ps = 0  -> DECSED and DECSEL can erase (default).
            Ps = 1  -> DECSED and DECSEL cannot erase.
            Ps = 2  -> DECSED and DECSEL can erase.

CSI # q   Pop video attributes from stack (XTPOPSGR), xterm.  This is an
          alias for CSI # } , used to work around language limitations
          of C#.

CSI Ps ; Ps r
          Set Scrolling Region [top;bottom] (default = full size of
          window) (DECSTBM), VT100.

CSI ? Pm r
          Restore DEC Private Mode Values (XTRESTORE), xterm.  The value
          of Ps previously saved is restored.  Ps values are the same as
          for DECSET.

          Like Restore Cursor (DECRC), this uses a one-level cache.
          Unlike Restore Cursor, specific settings can be saved and
          restored independently.  Only those modes listed as parameters
          are restored.

CSI Pt ; Pl ; Pb ; Pr ; Pm $ r
          Change Attributes in Rectangular Area (DECCARA), VT400 and up.
            Pt ; Pl ; Pb ; Pr denotes the rectangle.
            Pm denotes the SGR attributes to change: 0 , 1 , 4 , 5 , 7 ,
          8 .  Setting SGR 0  resets modes 1 , 4 , 5 , 7 .  Those modes
          can be individually reset with SGR 2 2 , 2 4 , 2 5  and 2 7 .
          Setting SGR 8  is an xterm extension; it may be reset with SGR
          2 8 .  See DECSACE.

CSI s     Save cursor, available only when DECLRMM is disabled (SCOSC,
          also ANSI.SYS).

CSI Pl ; Pr s
          Set left and right margins (DECSLRM), VT420 and up.  This is
          available only when DECLRMM is enabled.

CSI > Ps s
          Set/reset shift-escape options (XTSHIFTESCAPE), xterm.  This
          corresponds to the shiftEscape resource.

          Valid values for the parameter:
            Ps = 0  -> allow shift-key to override mouse protocol.
            Ps = 1  -> conditionally allow shift-key as modifier in
          mouse protocol.

          These resource values are disallowed in the control sequence:
            Ps = 2  -> always allow shift-key as modifier in mouse
          protocol.
            Ps = 3  -> never allow shift-key as modifier in mouse
          protocol.

          If no parameter is given, xterm uses the default, which is 0 .

CSI ? Pm s
          Save DEC Private Mode Values (XTSAVE), xterm.  Ps values are
          the same as for DECSET.

          Like Save Cursor (DECSC), this uses a one-level cache.  Unlike
          Save Cursor, specific settings can be saved and restored
          independently.  Only those modes listed as parameters are
          saved.

CSI Ps ; Ps ; Ps t
          Window manipulation (XTWINOPS), dtterm, extended by xterm.
          These controls may be disabled using the allowWindowOps
          resource.

          xterm uses Extended Window Manager Hints (EWMH) to maximize
          the window.  Some window managers have incomplete support for
          EWMH.  For instance, fvwm, flwm and quartz-wm advertise
          support for maximizing windows horizontally or vertically, but
          in fact equate those to the maximize operation.

          Valid values for the first (and any additional parameters)
          are:
            Ps = 1  -> De-iconify window.
            Ps = 2  -> Iconify window.
            Ps = 3 ;  x ;  y -> Move window to [x, y].
            Ps = 4 ;  height ;  width -> Resize the xterm window to
          given height and width in pixels.  Omitted parameters reuse
          the current height or width.  Zero parameters use the
          display's height or width.
            Ps = 5  -> Raise the xterm window to the front of the
          stacking order.
            Ps = 6  -> Lower the xterm window to the bottom of the
          stacking order.
            Ps = 7  -> Refresh the xterm window.
            Ps = 8 ;  height ;  width -> Resize the text area to given
          height and width in characters.  Omitted parameters reuse the
          current height or width.  Zero parameters use the display's
          height or width.
            Ps = 9 ;  0  -> Restore maximized window.
            Ps = 9 ;  1  -> Maximize window (i.e., resize to screen
          size).
            Ps = 9 ;  2  -> Maximize window vertically.
            Ps = 9 ;  3  -> Maximize window horizontally.
            Ps = 1 0 ;  0  -> Undo full-screen mode.
            Ps = 1 0 ;  1  -> Change to full-screen.
            Ps = 1 0 ;  2  -> Toggle full-screen.
            Ps = 1 1  -> Report xterm window state.
          If the xterm window is non-iconified, it returns CSI 1 t .
          If the xterm window is iconified, it returns CSI 2 t .
            Ps = 1 3  -> Report xterm window position.
          Note: X Toolkit positions can be negative, but the reported
          values are unsigned, in the range 0-65535.  Negative values
          correspond to 32768-65535.
          Result is CSI 3 ; x ; y t
            Ps = 1 3 ;  2  -> Report xterm text-area position.
          Result is CSI 3 ; x ; y t
            Ps = 1 4  -> Report xterm text area size in pixels.
          Result is CSI  4 ;  height ;  width t
            Ps = 1 4 ;  2  -> Report xterm window size in pixels.
          Normally xterm's window is larger than its text area, since it
          includes the frame (or decoration) applied by the window
          manager, as well as the area used by a scroll-bar.
          Result is CSI  4 ;  height ;  width t
            Ps = 1 5  -> Report size of the screen in pixels.
          Result is CSI  5 ;  height ;  width t
            Ps = 1 6  -> Report xterm character cell size in pixels.
          Result is CSI  6 ;  height ;  width t
            Ps = 1 8  -> Report the size of the text area in characters.
          Result is CSI  8 ;  height ;  width t
            Ps = 1 9  -> Report the size of the screen in characters.
          Result is CSI  9 ;  height ;  width t
            Ps = 2 0  -> Report xterm window's icon label.
          Result is OSC  L  label ST
            Ps = 2 1  -> Report xterm window's title.
          Result is OSC  l  label ST
            Ps = 2 2 ; 0  -> Save xterm icon and window title on stack.
            Ps = 2 2 ; 1  -> Save xterm icon title on stack.
            Ps = 2 2 ; 2  -> Save xterm window title on stack.
            Ps = 2 3 ; 0  -> Restore xterm icon and window title from
          stack.
            Ps = 2 3 ; 1  -> Restore xterm icon title from stack.
            Ps = 2 3 ; 2  -> Restore xterm window title from stack.
            Ps >= 2 4  -> Resize to Ps lines (DECSLPP), VT340 and VT420.
          xterm adapts this by resizing its window.

          XTWINOPS 2 2  (save/push title) and 2 3  (restore/pop title)
          accept an optional third parameter for direct access to the
          stack.  Parameters in the range 1 through 10, may be used to
          store the title into the stack or retrieve the title from the
          stack without pushing/popping.

CSI > Pm t
          This xterm control sets one or more features of the title
          modes (XTSMTITLE), xterm.  Each parameter enables a single
          feature.
            Ps = 0  -> Set window/icon labels using hexadecimal.
            Ps = 1  -> Query window/icon labels using hexadecimal.
            Ps = 2  -> Set window/icon labels using UTF-8.
            Ps = 3  -> Query window/icon labels using UTF-8.  (See
          discussion of Title Modes)

          If no parameters are given, title mode features are set to the
          initial (compiled-in) default.

CSI Ps SP t
          Set warning-bell volume (DECSWBV), VT520.
            Ps = 0  or 1  -> off.
            Ps = 2 , 3  or 4  -> low.
            Ps = 5 , 6 , 7 , or 8  -> high.

CSI Pt ; Pl ; Pb ; Pr ; Pm $ t
          Reverse Attributes in Rectangular Area (DECRARA), VT400 and
          up.
            Pt ; Pl ; Pb ; Pr denotes the rectangle.
            Pm denotes the attributes to reverse, i.e.,  0, 1, 4, 5, 7,
          8.  Reversing SGR 0 reverses modes 1, 4, 5, 7.  Reversing SGR
          8 is an xterm extension.  See DECSACE.

CSI u     Restore cursor (SCORC, also ANSI.SYS).

CSI & u   User-Preferred Supplemental Set (DECRQUPSS), VT320, VT510.
          Response is DECAUPSS.

CSI Ps SP u
          Set margin-bell volume (DECSMBV), VT520.
            Ps = 0 , 5 , 6 , 7 , or 8  -> high.
            Ps = 1  -> off.
            Ps = 2 , 3  or 4  -> low.

CSI " v   Request Displayed Extent (DECRQDE), VT340, VT420.
          Response is
            CSI Ph ; Pw ; Pc ; Pr ; Pp " w
          where
            Ph is the number of lines of the current page
            Pw is the number of columns of the current page
            Pc is the column number at the top-left of the window
            Pr is the row number at the top-left of the window
            Pp is the current page number

CSI Pt ; Pl ; Pb ; Pr ; Pp ; Pt ; Pl ; Pp $ v
          Copy Rectangular Area (DECCRA), VT400 and up.
            Pt ; Pl ; Pb ; Pr denotes the rectangle.
            Pp denotes the source page.
            Pt ; Pl denotes the target location.
            Pp denotes the target page.

CSI Ps $ w
          Request presentation state report (DECRQPSR), VT320 and up.
            Ps = 0  -> error.
            Ps = 1  -> cursor information report (DECCIR).
          Response is
            DCS 1 $ u Pt ST
          Refer to the VT420 programming manual, which requires six
          pages to document the data string Pt,
            Ps = 2  -> tab stop report (DECTABSR).
          Response is
            DCS 2 $ u Pt ST
          The data string Pt is a list of the tab-stops, separated by
          "/" characters.

CSI Pt ; Pl ; Pb ; Pr ' w
          Enable Filter Rectangle (DECEFR), VT420 and up.
          Parameters are [top;left;bottom;right].
          Defines the coordinates of a filter rectangle and activates
          it.  Anytime the locator is detected outside of the filter
          rectangle, an outside rectangle event is generated and the
          rectangle is disabled.  Filter rectangles are always treated
          as "one-shot" events.  Any parameters that are omitted default
          to the current locator position.  If all parameters are
          omitted, any locator motion will be reported.  DECELR always
          cancels any previous rectangle definition.

CSI Ps x  Request Terminal Parameters (DECREQTPARM).
          if Ps is a "0" (default) or "1", and xterm is emulating VT100,
          the control sequence elicits a response of the same form whose
          parameters describe the terminal:
            Ps -> the given Ps incremented by 2.
            Pn = 1  <- no parity.
            Pn = 1  <- eight bits.
            Pn = 1  <- 2 8  transmit 38.4k baud.
            Pn = 1  <- 2 8  receive 38.4k baud.
            Pn = 1  <- clock multiplier.
            Pn = 0  <- STP flags.

CSI Ps * x
          Select Attribute Change Extent (DECSACE), VT420 and up.
            Ps = 0  -> from start to end position, wrapped.
            Ps = 1  -> from start to end position, wrapped.
            Ps = 2  -> rectangle (exact).
          Modes 0  and 1  are the stream modes of the DECCARA and
          DECRARA controls.  There are several aspects to stream versus
          rectangle modes:
          1) In both stream and rectangle modes, the row- and column-
          positions are affected by Origin Mode.
          2) In rectangle mode, cells outside the row- and column-
          positions are unaffected.  In stream mode, the row- and
          column-positions are the starting and ending cells, with
          wrapping which ignores Origin Mode.
          3) In stream mode, those controls affect only cells where a
          character was drawn.  In rectangle mode, cells where no
          character was drawn are first filled in with a space.

CSI Pc ; Pt ; Pl ; Pb ; Pr $ x
          Fill Rectangular Area (DECFRA), VT420 and up.
            Pc is the character to use.
            Pt ; Pl ; Pb ; Pr denotes the rectangle.

CSI Ps # y
          Select checksum extension (XTCHECKSUM), xterm.  The bits of Ps
          modify the calculation of the checksum returned by DECRQCRA:
            0  -> do not negate the result.
            1  -> do not report the VT100 video attributes.
            2  -> do not omit checksum for blanks.
            3  -> omit checksum for cells not explicitly initialized.
            4  -> do not mask cell value to 8 bits or ignore combining
          characters.

CSI Pi ; Pg ; Pt ; Pl ; Pb ; Pr * y
          Request Checksum of Rectangular Area (DECRQCRA), VT420 and up.
          Response is
          DCS Pi ! ~ x x x x ST
            Pi is the request id.
            Pg is the page number.
            Pt ; Pl ; Pb ; Pr denotes the rectangle.
            The x's are hexadecimal digits 0-9 and A-F.

CSI Ps ; Pu ' z
          Enable Locator Reporting (DECELR).
          Valid values for the first parameter:
            Ps = 0  -> Locator disabled (default).
            Ps = 1  -> Locator enabled.
            Ps = 2  -> Locator enabled for one report, then disabled.
          The second parameter specifies the coordinate unit for locator
          reports.
          Valid values for the second parameter:
            Pu = 0  or omitted -> default to character cells.
            Pu = 1  <- device physical pixels.
            Pu = 2  <- character cells.

CSI Pt ; Pl ; Pb ; Pr $ z
          Erase Rectangular Area (DECERA), VT400 and up.
            Pt ; Pl ; Pb ; Pr denotes the rectangle.

CSI Pm ' {
          Select Locator Events (DECSLE).
          Valid values for the first (and any additional parameters)
          are:
            Ps = 0  -> only respond to explicit host requests (DECRQLP).
          This is default.  It also cancels any filter rectangle.
            Ps = 1  -> report button down transitions.
            Ps = 2  -> do not report button down transitions.
            Ps = 3  -> report button up transitions.
            Ps = 4  -> do not report button up transitions.

CSI # {
CSI Pm # {
          Push video attributes onto stack (XTPUSHSGR), xterm.  The
          optional parameters correspond to the SGR encoding for video
          attributes, except for colors (which do not have a unique SGR
          code):
            Ps = 1  -> Bold.
            Ps = 2  -> Faint.
            Ps = 3  -> Italicized.
            Ps = 4  -> Underlined.
            Ps = 5  -> Blink.
            Ps = 7  -> Inverse.
            Ps = 8  -> Invisible.
            Ps = 9  -> Crossed-out characters.
            Ps = 2 1  -> Doubly-underlined.
            Ps = 3 0  -> Foreground color.
            Ps = 3 1  -> Background color.

          If no parameters are given, all of the video attributes are
          saved.  The stack is limited to 10 levels.

CSI Pt ; Pl ; Pb ; Pr $ {
          Selective Erase Rectangular Area (DECSERA), VT400 and up.
            Pt ; Pl ; Pb ; Pr denotes the rectangle.

CSI Pt ; Pl ; Pb ; Pr # |
          Report selected graphic rendition (XTREPORTSGR), xterm.  The
          response is an SGR sequence which contains the attributes
          which are common to all cells in a rectangle.
            Pt ; Pl ; Pb ; Pr denotes the rectangle.

CSI Ps $ |
          Select columns per page (DECSCPP), VT340.
            Ps = 0  -> 80 columns, default if Ps omitted.
            Ps = 8 0  -> 80 columns.
            Ps = 1 3 2  -> 132 columns.

CSI Ps ' |
          Request Locator Position (DECRQLP).
          Valid values for the parameter are:
            Ps = 0 , 1 or omitted -> transmit a single DECLRP locator
          report.

          If Locator Reporting has been enabled by a DECELR, xterm will
          respond with a DECLRP Locator Report.  This report is also
          generated on button up and down events if they have been
          enabled with a DECSLE, or when the locator is detected outside
          of a filter rectangle, if filter rectangles have been enabled
          with a DECEFR.

            <- CSI Pe ; Pb ; Pr ; Pc ; Pp &  w

          Parameters are [event;button;row;column;page].
          Valid values for the event:
            Pe = 0  <- locator unavailable - no other parameters sent.
            Pe = 1  <- request - xterm received a DECRQLP.
            Pe = 2  <- left button down.
            Pe = 3  <- left button up.
            Pe = 4  <- middle button down.
            Pe = 5  <- middle button up.
            Pe = 6  <- right button down.
            Pe = 7  <- right button up.
            Pe = 8  <- M4 button down.
            Pe = 9  <- M4 button up.
            Pe = 1 0  <- locator outside filter rectangle.
          The "button" parameter is a bitmask indicating which buttons
          are pressed:
            Pb = 0  <- no buttons down.
            Pb & 1  <- right button down.
            Pb & 2  <- middle button down.
            Pb & 4  <- left button down.
            Pb & 8  <- M4 button down.
          The "row" and "column" parameters are the coordinates of the
          locator position in the xterm window, encoded as ASCII
          decimal.
          The "page" parameter is not used by xterm.

CSI Ps * |
          Select number of lines per screen (DECSNLS), VT420 and up.

CSI # }   Pop video attributes from stack (XTPOPSGR), xterm.  Popping
          restores the video-attributes which were saved using XTPUSHSGR
          to their previous state.

CSI Ps ; Pf ; Pb , |
          Assign Color (DECAC), VT525 only.
            Ps selects the color item
            Pf is the foreground color index 0..15
            Pb is the background color index 0..15
          Color items:
            Ps = 1  -> normal text
            Ps = 2  -> window frame
          xterm uses the SGR color palette with DECAC color item 1 to
          update the VT100 window colors, like OSC  1 0  and 1 1 .

CSI Ps ; Pf ; Pb , }
          Alternate Text Color (DECATC), VT525 only.  This feature
          specifies the colors to use when DECSTGLT is selected to 1 or
          2.
            Ps selects attribute combinations
            Pf is the foreground color index 0..15
            Pb is the background color index 0..15
          Attribute combinations:
            Ps = 0  -> normal text
            Ps = 1  -> bold
            Ps = 2  -> reverse
            Ps = 3  -> underline
            Ps = 4  -> blink
            Ps = 5  -> bold reverse
            Ps = 6  -> bold underline
            Ps = 7  -> bold blink
            Ps = 8  -> reverse underline
            Ps = 9  -> reverse blink
            Ps = 1 0  -> underline blink
            Ps = 1 1  -> bold reverse underline
            Ps = 1 2  -> bold reverse blink
            Ps = 1 3  -> bold underline blink
            Ps = 1 4  -> reverse underline blink
            Ps = 1 5  -> bold reverse underline blink

CSI Ps ' }
          Insert Ps Column(s) (default = 1) (DECIC), VT420 and up.

CSI Ps $ }
          Select active status display (DECSASD), VT320 and up.
            Ps = 0  -> main (default)
            Ps = 1  -> status line

CSI Ps ' ~
          Delete Ps Column(s) (default = 1) (DECDC), VT420 and up.

CSI Ps $ ~
          Select status line type (DECSSDT), VT320 and up.
            Ps = 0  -> none
            Ps = 1  -> indicator (default)
            Ps = 2  -> host-writable.


Operating System Commands

OSC Ps ; Pt BEL

OSC Ps ; Pt ST
          Set Text Parameters, xterm.  Some control sequences return
          information:
          o   For colors and font, if Pt is a "?", the control sequence
              elicits a response which consists of the control sequence
              which would set the corresponding value.
          o   A few of these control sequences began with dtterm (codes
              0 , 1 , and 2 ).  Code 3  in dtterm sets the working
              directory for the next session.  XTerm does that with the
              spawn-new-terminal action.

          XTerm accepts either BEL  or ST  for terminating OSC
          sequences, and when returning information, uses the same
          terminator used in a query.  While the latter is preferred,
          the former is supported for legacy applications:
          o   Although documented in the changes for X.V10R4 (December
              1986), BEL  as a string terminator dates from X11R4
              (December 1989).
          o   Since XFree86-3.1.2Ee (August 1996), xterm has accepted ST
              (the documented string terminator in ECMA-48).

          Ps specifies the type of operation to perform:
            Ps = 0  -> Change Icon Name and Window Title to Pt.
            Ps = 1  -> Change Icon Name to Pt.
            Ps = 2  -> Change Window Title to Pt.
            Ps = 3  -> Set X property on top-level window.  Pt should be
          in the form "prop=value", or just "prop" to delete the
          property.
            Ps = 4 ; c ; spec -> Change Color Number c to the color
          specified by spec.

          The spec can be a name or RGB specification as per
          XParseColor.  Any number of c/spec pairs may be given.  The
          color numbers correspond to the ANSI colors 0-7, their bright
          versions 8-15, and if supported, the remainder of the 88-color
          or 256-color table.

          If a "?" is given rather than a name or RGB specification,
          xterm replies with a control sequence of the same form which
          can be used to set the corresponding color.  Because more than
          one pair of color number and specification can be given in one
          control sequence, xterm can make more than one reply.

            Ps = 5 ; c ; spec -> Change Special Color Number c to the
          color specified by spec.

          The spec parameter can be a name or RGB specification as per
          XParseColor.  Any number of c/spec pairs may be given.  The
          special colors can also be set by adding the maximum number of
          colors (e.g., 88 or 256) to these codes in an OSC 4  control:

              Pc = 0  <- resource colorBD (BOLD).
              Pc = 1  <- resource colorUL (UNDERLINE).
              Pc = 2  <- resource colorBL (BLINK).
              Pc = 3  <- resource colorRV (REVERSE).
              Pc = 4  <- resource colorIT (ITALIC).

            Ps = 6 ; c ; f -> Enable/disable Special Color Number c.
          The second parameter tells xterm to enable the corresponding
          color mode if nonzero, disable it if zero.  OSC 6  is the same
          as OSC 1 0 6 .

          If no parameters are given, this control has no effect.

          The 10 colors (below) which may be set or queried using 1 0
          through 1 9  are denoted dynamic colors, since the
          corresponding control sequences were the first means for
          setting xterm's colors dynamically, i.e., after it was
          started.  They are not the same as the ANSI colors (however,
          the dynamic text foreground and background colors are used
          when ANSI colors are reset using SGR 3 9  and 4 9 ,
          respectively).  These controls may be disabled using the
          allowColorOps resource.  At least one parameter is expected
          for Pt.  Each successive parameter changes the next color in
          the list.  The value of Ps tells the starting point in the
          list.  The colors are specified by name or RGB specification
          as per XParseColor.

               Resource                 Description
               -----------------------+-----------------------------
               foreground             | VT100 text foreground color
               background             | VT100 text background color
               cursorColor            | text cursor color
               pointerColor           | pointer foreground color
               pointerColorBackground | pointer background
               (foreground)           | Tektronix foreground color
               (background)           | Tektronix background color
               highlightColor         | highlight background color
               (cursorColor)          | Tektronix cursor color
               highlightTextColor     | highlight foreground color
               -----------------------+-----------------------------

          The Tektronix colors are initially set from the VT100 colors,
          but after that can be set independently using these control
          sequences.

          If a "?" is given rather than a name or RGB specification,
          xterm replies with a control sequence of the same form which
          can be used to set the corresponding dynamic color.  Because
          more than one pair of color number and specification can be
          given in one control sequence, xterm can make more than one
          reply.

            Ps = 1 0  -> Change VT100 text foreground color to Pt.
            Ps = 1 1  -> Change VT100 text background color to Pt.
            Ps = 1 2  -> Change text cursor color to Pt.
            Ps = 1 3  -> Change pointer foreground color to Pt.
            Ps = 1 4  -> Change pointer background color to Pt.
            Ps = 1 5  -> Change Tektronix foreground color to Pt.
            Ps = 1 6  -> Change Tektronix background color to Pt.
            Ps = 1 7  -> Change highlight background color to Pt.
            Ps = 1 8  -> Change Tektronix cursor color to Pt.
            Ps = 1 9  -> Change highlight foreground color to Pt.

            Ps = 2 2  -> Change pointer cursor shape to Pt.  The
          parameter Pt sets the pointerShape resource.  If Pt is empty,
          or does not match any of the standard names, xterm uses the
          resource's default "xterm" shape.

            Ps = 4 6  -> Change Log File to Pt.  The parameter Pt sets
          the logFile resource.  Logging is normally disabled by a
          compile-time option.

            Ps = 5 0  -> Set Font to Pt.  These controls may be disabled
          using the allowFontOps resource.  If Pt begins with a "#",
          index in the font menu, relative (if the next character is a
          plus or minus sign) or absolute.  A number is expected but not
          required after the sign (the default is the current entry for
          relative, zero for absolute indexing).

          The same rule (plus or minus sign, optional number) is used
          when querying the font.  The remainder of Pt is ignored.

          A font can be specified after a "#" index expression, by
          adding a space and then the font specifier.

          If the TrueType Fonts menu entry is set (the renderFont
          resource), then this control sets/queries the faceName
          resource.

            Ps = 5 1  -> reserved for Emacs shell.

            Ps = 5 2  -> Manipulate Selection Data.  These controls may
          be disabled using the allowWindowOps resource.  The parameter
          Pt is parsed as
               Pc ; Pd

          The first, Pc, may contain zero or more characters from the
          set c , p , q , s , 0 , 1 , 2 , 3 , 4 , 5 , 6 , and 7 .  It is
          used to construct a list of selection parameters for
          clipboard, primary, secondary, select, or cut-buffers 0
          through 7 respectively, in the order given.  If the parameter
          is empty, xterm uses s 0 , to specify the configurable
          primary/clipboard selection and cut-buffer 0.

          The second parameter, Pd, gives the selection data.  Normally
          this is a string encoded in base64 (RFC-4648).  The data
          becomes the new selection, which is then available for pasting
          by other applications.

          If the second parameter is a ? , xterm replies to the host
          with the selection data encoded using the same protocol.  It
          uses the first selection found by asking successively for each
          item from the list of selection parameters.

          If the second parameter is neither a base64 string nor ? ,
          then the selection is cleared.

            Ps = 6 0  -> Query allowed features (XTQALLOWED).  XTerm
          replies with

            OSC 6 0  ; Pt ST

          where Pt is a comma-separated list of the allowed optional
          runtime feature categories, i.e., zero or more of these
          resource names:

            allowColorOps
            allowFontOps
            allowMouseOps
            allowPasteControls
            allowTcapOps
            allowTitleOps
            allowWindowOps

          Except for allowPasteControls, those resources can be enabled
          or disabled at runtime using menus.  They cannot be changed
          using control sequences.

            Ps = 6 1  -> Query disallowed features (XTQDISALLOWED).  The
          second parameter (i.e., the main feature category) must be one
          of the resource names returned by OSC 6 0 .  XTerm replies
          with

            OSC 6 1  ; Pt ST

          where Pt is a comma-separated list of the optional runtime
          feature subcategories which would be disallowed if the main
          feature is disabled.

            Ps = 6 2  -> Query allowable features (XTQALLOWABLE).  The
          second parameter (i.e., the main feature category) must be one
          of the resource names that might be returned by OSC 6 0 .
          XTerm replies with

            OSC 6 2  ; Pt ST

          where Pt is a comma-separated list of the optional runtime
          feature subcategories which correspond to the main feature
          category.

            Ps = 1 0 4 ; c -> Reset Color Number c.  It is reset to the
          color specified by the corresponding X resource.  Any number
          of c parameters may be given.  These parameters correspond to
          the ANSI colors 0-7, their bright versions 8-15, and if
          supported, the remainder of the 88-color or 256-color table.
          If no parameters are given, the entire table will be reset.

            Ps = 1 0 5 ; c -> Reset Special Color Number c.  It is reset
          to the color specified by the corresponding X resource.  Any
          number of c parameters may be given.  These parameters
          correspond to the special colors which can be set using an OSC
          5  control (or by adding the maximum number of colors using an
          OSC 4  control).

          If no parameters are given, all special colors will be reset.

            Ps = 1 0 6 ; c ; f -> Enable/disable Special Color Number c.
          The second parameter tells xterm to enable the corresponding
          color mode if nonzero, disable it if zero.

              Pc = 0  <- resource colorBDMode (BOLD).
              Pc = 1  <- resource colorULMode (UNDERLINE).
              Pc = 2  <- resource colorBLMode (BLINK).
              Pc = 3  <- resource colorRVMode (REVERSE).
              Pc = 4  <- resource colorITMode (ITALIC).
              Pc = 5  <- resource colorAttrMode (Override ANSI).

          If no parameters are given, this control has no effect.

          The dynamic colors can also be reset to their default
          (resource) values:
            Ps = 1 1 0  -> Reset VT100 text foreground color.
            Ps = 1 1 1  -> Reset VT100 text background color.
            Ps = 1 1 2  -> Reset text cursor color.
            Ps = 1 1 3  -> Reset pointer foreground color.
            Ps = 1 1 4  -> Reset pointer background color.
            Ps = 1 1 5  -> Reset Tektronix foreground color.
            Ps = 1 1 6  -> Reset Tektronix background color.
            Ps = 1 1 7  -> Reset highlight color.
            Ps = 1 1 8  -> Reset Tektronix cursor color.
            Ps = 1 1 9  -> Reset highlight foreground color.

            Ps = I  ; c -> Set icon to file.  Sun shelltool, CDE dtterm.
          The file is expected to be XPM format, and uses the same
          search logic as the iconHint resource.

            Ps = l  ; c -> Set window title.  Sun shelltool, CDE dtterm.

            Ps = L  ; c -> Set icon label.  Sun shelltool, CDE dtterm.


Privacy Message

PM Pt ST  xterm implements no PM  functions; Pt is ignored.  Pt need not
          be printable characters.


Special Keyboard Keys

Terminal keyboards have two types of keys:

o   ordinary keys, which you would use as data, e.g., in a text file,
    and

o   special keys, which you would use to tell xterm to perform some
    action.

XTerm detects all of these keys via X key-press and key-release events.
It uses the translations resource to decide what to do with these
events.

o   Ordinary keys are handled with the insert-seven-bit action, or the
    insert-eight-bit action.

o   Special keys may be handled with other resources.  However, xterm
    also has built-in logic to map commonly-used special keys into
    characters which your keypress sends to the application running in
    xterm.

Special keyboard keys send control characters or escape sequences.  This
is a convention, making it convenient for applications to detect these
keys, rather than a standard.


Alt and Meta Keys

Many keyboards have keys labeled "Alt".  Few have keys labeled "Meta".
However, xterm's default translations use the Meta modifier.  Common
keyboard configurations assign the Meta modifier to an "Alt" key.  By
using xmodmap one may have the modifier assigned to a different key, and
have "real" alt and meta keys.  Here is an example:

     ! put meta on mod3 to distinguish it from alt
     keycode 64 = Alt_L
     clear mod1
     add mod1 = Alt_L
     keycode 115 = Meta_L
     clear mod3
     add mod3 = Meta_L

The metaSendsEscape resource (and altSendsEscape if altIsNotMeta is set)
can be used to control the way the Meta modifier applies to ordinary
keys unless the modifyOtherKeys resource is set:

o   prefix a key with the ESC  character.

o   shift the key from codes 0-127 to 128-255 by adding 128.

The table shows the result for a given character "x" with modifiers
according to the default translations with the resources set on or off.
This assumes altIsNotMeta is set:

       key          altSendsEscape   metaSendsEscape   result
       -----------+----------------+-----------------+------------
       x          | off            | off             | x
       Meta-x     | off            | off             | shift
       Alt-x      | off            | off             | shift
       Alt+Meta-x | off            | off             | shift
       x          | ON             | off             | x
       Meta-x     | ON             | off             | shift
       Alt-x      | ON             | off             | ESC  x
       Alt+Meta-x | ON             | off             | ESC  shift
       x          | off            | ON              | x
       Meta-x     | off            | ON              | ESC  x
       Alt-x      | off            | ON              | shift
       Alt+Meta-x | off            | ON              | ESC  shift
       x          | ON             | ON              | x
       Meta-x     | ON             | ON              | ESC  x
       Alt-x      | ON             | ON              | ESC  x
       Alt+Meta-x | ON             | ON              | ESC  x
       -----------+----------------+-----------------+------------

When modifyOtherKeys is set, ordinary keys may be sent as escape
sequences:

o   When modifyOtherKeys is set to 1, the usual shift- and control-
    modifiers work as expected, but other modifiers (such as alt- and
    meta-modifiers) cause ordinary keys to be encoded as if they were
    function-keys.  For example, alt-Tab sends CSI 2 7 ; 3 ; 9 ~ (the
    second parameter is "3" for alt, and the third parameter is the
    ASCII value of tab, "9").

    Ordinary characters can have non-ASCII values.  XTerm uses the X11
    libraries to obtain the character encoding used for a given keysym
    (key symbol).  The X11 keysymdef.h header lists 2104 predefined key
    symbols, as well as documenting how arbitrary Unicode values are
    represented.  The other *keysym.h headers add 480 symbols.

o   When modifyOtherKeys is set to 2, all of the modifiers apply.  For
    example, shift-Tab sends CSI 2 7 ; 2 ; 9 ~ rather than CSI Z (the
    second parameter is "2" for shift).

o   If modifyOtherKeys is set to 3, unmodified keys also are sent as
    escape sequences.  For example, space sends CSI 2 7 ; 1 ; 3 2 ~

There are a few variations available; they can be set statically with
resource values or dynamically using control sequences:

o   The formatOtherKeys resource tells xterm to change the format of the
    escape sequences sent when modifyOtherKeys applies.  When
    modifyOtherKeys is set to 1, for example alt-Tab sends CSI 9 ; 3 u
    (changing the order of parameters).  One drawback to this format is
    that applications may confuse it with CSI u  (restore-cursor).

    The resource value can be updated with a corresponding control
    sequence.

o   The modifyOtherKeys resource can be updated via a corresponding
    control sequence.  The control sequence accepts a single
    subparameter, which is interpreted as a mask of modifier bits to
    factor out of the parameter encoding of the escape sequence.  For
    example CSI > 4 : 1  m factors out the shift modifier.

Some of the predefined key symbols can be automatically derived, or are
duplicates.  That leaves about half of the key symbols which xterm may
encounter.  Most of these are non-character key symbols which may be
assigned to positions on a keyboard.

o   The most common non-character key symbols are in the range 0xfd00 to
    0xffff.  XTerm maps them to the Unicode BMP private use area
    beginning at U+E001.  These account for about a quarter (329) of the
    non-character symbols.

o   The other non-character key symbols are vendor/platform specific.
    Those use codes above 0x10000000.  XTerm maps them to the Unicode
    BMP private use area beginning at U+F0000.

o   The remaining non-Unicode values are characters used in the DEC
    Technical character set.  XTerm maps them to the Unicode BMP private
    use area beginning at U+EEEE.

XTerm has additional resource settings (and control sequences) to send
these non-character symbols as escape sequences.  The Xutil.h header
defines some of the macros which xterm uses for categorizing these non-
character symbols:

IsKeypadKey(keysym)
          is used for the numeric keypad (see modifyKeypadKeys and
          formatKeypadKeys).

IsPrivateKeypadKey(keysym)
          is unused.

IsCursorKey(keysym)
          is used for the cursor keys, including Home and End (see
          modifyCursorKeys and formatCursorKeys).  XTerm makes a special
          check for the PC keyboard's editing keypad, which is not
          handled by the Xutil.h macros.

IsPFKey(keysym)

IsFunctionKey(keysym)

IsMiscFunctionKey(keysym)
          are used for function keys (see modifyFunctionKeys and
          formatFunctionKeys).

IsModifierKey(keysym)
          is used for modifier keys (see modifyModifierKeys and
          formatModifierKeys).

These macros account for 162 of the 329 non-Unicode values in the BMP.

The xterm FAQ sections

   How can my program distinguish control-I from tab?

   XTerm - "Other" Modified Keys

go into greater detail on this topic.


PC-Style Function Keys

If xterm does minimal translation of the function keys, it usually does
this with a PC-style keyboard, so PC-style function keys result.  Sun
keyboards are similar to PC keyboards.  Both have cursor and scrolling
operations printed on the keypad, which duplicate the smaller cursor and
scrolling keypads.

X does not predefine NumLock (used for VT220 keyboards) or Alt (used as
an extension for the Sun/PC keyboards) as modifiers.  These keys are
recognized as modifiers when enabled by the numLock resource, or by the
"DECSET 1 0 3 5 " control sequence.

The cursor keys transmit the following escape sequences depending on the
mode specified via the DECCKM escape sequence.

                  Key            Normal     Application
                  -------------+----------+-------------
                  Cursor Up    | CSI A    | SS3 A
                  Cursor Down  | CSI B    | SS3 B
                  Cursor Right | CSI C    | SS3 C
                  Cursor Left  | CSI D    | SS3 D
                  -------------+----------+-------------

The home- and end-keys (unlike PageUp and other keys also on the 6-key
editing keypad) are considered "cursor keys" by xterm.  Their mode is
also controlled by the DECCKM escape sequence:

                    Key        Normal     Application
                    ---------+----------+-------------
                    Home     | CSI H    | SS3 H
                    End      | CSI F    | SS3 F
                    ---------+----------+-------------

The application keypad transmits the following escape sequences
depending on the mode specified via the DECKPNM and DECKPAM escape
sequences.  Use the NumLock key to override the application mode.

Not all keys are present on the Sun/PC keypad (e.g., PF1, Tab), but are
supported by the program.

      Key              Numeric    Application   Terminfo   Termcap
      ---------------+----------+-------------+----------+----------
      Space          | SP       | SS3 SP      | -        | -
      Tab            | TAB      | SS3 I       | -        | -
      Enter          | CR       | SS3 M       | kent     | @8
      PF1            | SS3 P    | SS3 P       | kf1      | k1
      PF2            | SS3 Q    | SS3 Q       | kf2      | k2
      PF3            | SS3 R    | SS3 R       | kf3      | k3
      PF4            | SS3 S    | SS3 S       | kf4      | k4
      * (multiply)   | *        | SS3 j       | -        | -
      + (add)        | +        | SS3 k       | -        | -
      , (comma)      | ,        | SS3 l       | -        | -
      - (minus)      | -        | SS3 m       | -        | -
      . (Delete)     | .        | CSI 3 ~     | -        | -
      / (divide)     | /        | SS3 o       | -        | -
      0 (Insert)     | 0        | CSI 2 ~     | -        | -
      1 (End)        | 1        | SS3 F       | kc1      | K4
      2 (DownArrow)  | 2        | CSI B       | -        | -
      3 (PageDown)   | 3        | CSI 6 ~     | kc3      | K5
      4 (LeftArrow)  | 4        | CSI D       | -        | -
      5 (Begin)      | 5        | CSI E       | kb2      | K2
      6 (RightArrow) | 6        | CSI C       | -        | -
      7 (Home)       | 7        | SS3 H       | ka1      | K1
      8 (UpArrow)    | 8        | CSI A       | -        | -
      9 (PageUp)     | 9        | CSI 5 ~     | ka3      | K3
      = (equal)      | =        | SS3 X       | -        | -
      ---------------+----------+-------------+----------+----------

They also provide 12 function keys, as well as a few other special-
purpose keys:

                       Key        Escape Sequence
                       ---------+-----------------
                       F1       | SS3 P
                       F2       | SS3 Q
                       F3       | SS3 R
                       F4       | SS3 S
                       F5       | CSI 1 5 ~
                       F6       | CSI 1 7 ~
                       F7       | CSI 1 8 ~
                       F8       | CSI 1 9 ~
                       F9       | CSI 2 0 ~
                       F10      | CSI 2 1 ~
                       F11      | CSI 2 3 ~
                       F12      | CSI 2 4 ~
                       ---------+-----------------

Note that F1 through F4 are prefixed with SS3 , while the other keys are
prefixed with CSI .  Older versions of xterm implement different escape
sequences for F1 through F4, with a CSI  prefix.  These can be activated
by setting the oldXtermFKeys resource.  However, since they do not
correspond to any hardware terminal, they have been deprecated.  (The
DEC VT220 reserves F1 through F5 for local functions such as Setup).

                       Key        Escape Sequence
                       ---------+-----------------
                       F1       | CSI 1 1 ~
                       F2       | CSI 1 2 ~
                       F3       | CSI 1 3 ~
                       F4       | CSI 1 4 ~
                       ---------+-----------------

In normal mode, i.e., a Sun/PC keyboard when the sunKeyboard resource is
false (and none of the other keyboard resources such as oldXtermFKeys
resource is set), xterm encodes function key modifiers as parameters
appended before the final character of the control sequence.  As a
special case, the SS3  sent before F1 through F4 is altered to CSI  when
sending a function key modifier as a parameter.

                    Code     Modifiers
                  ---------+---------------------------
                     2     | Shift
                     3     | Alt
                     4     | Shift + Alt
                     5     | Control
                     6     | Shift + Control
                     7     | Alt + Control
                     8     | Shift + Alt + Control
                     9     | Meta
                     10    | Meta + Shift
                     11    | Meta + Alt
                     12    | Meta + Alt + Shift
                     13    | Meta + Ctrl
                     14    | Meta + Ctrl + Shift
                     15    | Meta + Ctrl + Alt
                     16    | Meta + Ctrl + Alt + Shift
                  ---------+---------------------------

For example, shift-F5 would be sent as CSI 1 5 ; 2 ~

If the alwaysUseMods resource is set, the Meta modifier also is
recognized, making parameters 9 through 16.

The codes used for the PC-style function keys were inspired by a feature
of the VT510, referred to in its reference manual as DECFNK.  In the
DECFNK scheme, codes 2-8 identify modifiers for function-keys and
cursor-, editing-keypad keys.  Unlike xterm, the VT510 limits the
modifiers which can be used with cursor- and editing-keypad keys.
Although the name "DECFNK" implies that it is a mode, the VT510 manual
mentions it only as a feature, which (like xterm) interacts with the
DECUDK feature.  Unlike xterm, VT510/VT520 provide an extension to
DECUDK (DECPFK and DECPAK) which apparently was the reason for the
feature in those terminals, i.e., for identifying a programmable key
rather than making it simple for applications to obtain modifier
information.  It is not described in the related VT520 manual.  Neither
manual was readily available at the time the feature was added to xterm.

On the other hand, the VT510 and VT520 reference manuals do document a
related feature.  That is its emulation of the SCO console, which is
similar to the "xterm-sco" terminal description.  The SCO console
function-keys are less useful to applications developers than the
approach used by xterm because

o   the relationship between modifiers and the characters sent by
    function-keys is not readily apparent, and

o   the scheme is not extensible, i.e., it is an ad hoc assignment
    limited to two modifiers (shift and control).


VT220-Style Function Keys

However, xterm is most useful as a DEC VT102 or VT220 emulator.  Set the
sunKeyboard resource to true to force a Sun/PC keyboard to act like a
VT220 keyboard.

The VT102/VT220 application keypad transmits unique escape sequences in
application mode, which are distinct from the cursor and scrolling
keypad:

            Key            Numeric    Application   VT100?
            -------------+----------+-------------+----------
            Space        | SP       | SS3 SP      | no
            Tab          | TAB      | SS3 I       | no
            Enter        | CR       | SS3 M       | yes
            PF1          | SS3 P    | SS3 P       | yes
            PF2          | SS3 Q    | SS3 Q       | yes
            PF3          | SS3 R    | SS3 R       | yes
            PF4          | SS3 S    | SS3 S       | yes
            * (multiply) | *        | SS3 j       | no
            + (add)      | +        | SS3 k       | no
            , (comma)    | ,        | SS3 l       | yes
            - (minus)    | -        | SS3 m       | yes
            . (period)   | .        | SS3 n       | yes
            / (divide)   | /        | SS3 o       | no
            0            | 0        | SS3 p       | yes
            1            | 1        | SS3 q       | yes
            2            | 2        | SS3 r       | yes
            3            | 3        | SS3 s       | yes
            4            | 4        | SS3 t       | yes
            5            | 5        | SS3 u       | yes
            6            | 6        | SS3 v       | yes
            7            | 7        | SS3 w       | yes
            8            | 8        | SS3 x       | yes
            9            | 9        | SS3 y       | yes
            = (equal)    | =        | SS3 X       | no
            -------------+----------+-------------+----------

The VT100/VT220 keypad did not have all of those keys.  They were
implemented in xterm in X11R1 (1987), defining a mapping of all X11 keys
which might be provided on a keypad.  For instance, a Sun4/II type-4
keyboard provided "=" (equal), "/" (divide), and "*" (multiply).

While the VT420 provided the same keypad, the VT520 used a PC-keyboard.
Because that keyboard's keypad lacks the "," (comma), it was not
possible to use EDT's delete-character function with the keypad.  XTerm
solves that problem for the VT220-keyboard configuration by mapping

  Ctrl +  to ,  and
  Ctrl -  to -

The VT220 provides a 6-key editing keypad, which is analogous to that on
the PC keyboard.  It is not affected by DECCKM or DECKPNM/DECKPAM:

                   Key        Normal     Application
                   ---------+----------+-------------
                   Insert   | CSI 2 ~  | CSI 2 ~
                   Delete   | CSI 3 ~  | CSI 3 ~
                   Home     | CSI 1 ~  | CSI 1 ~
                   End      | CSI 4 ~  | CSI 4 ~
                   PageUp   | CSI 5 ~  | CSI 5 ~
                   PageDown | CSI 6 ~  | CSI 6 ~
                   ---------+----------+-------------

The VT220 provides 8 additional function keys.  With a Sun/PC keyboard,
access these keys by Control/F1 for F13, etc.

                       Key        Escape Sequence
                       ---------+-----------------
                       F13      | CSI 2 5 ~
                       F14      | CSI 2 6 ~
                       F15      | CSI 2 8 ~
                       F16      | CSI 2 9 ~
                       F17      | CSI 3 1 ~
                       F18      | CSI 3 2 ~
                       F19      | CSI 3 3 ~
                       F20      | CSI 3 4 ~
                       ---------+-----------------

VT52-Style Function Keys

A VT52 does not have function keys, but it does have a numeric keypad
and cursor keys.  They differ from the other emulations by the prefix.
Also, the cursor keys do not change:

                   Key            Normal/Application
                   -------------+--------------------
                   Cursor Up    | ESC A
                   Cursor Down  | ESC B
                   Cursor Right | ESC C
                   Cursor Left  | ESC D
                   -------------+--------------------

The keypad is similar:

            Key            Numeric    Application   VT52?
            -------------+----------+-------------+----------
            Space        | SP       | ESC ? SP    | no
            Tab          | TAB      | ESC ? I     | no
            Enter        | CR       | ESC ? M     | no
            PF1          | ESC P    | ESC P       | yes
            PF2          | ESC Q    | ESC Q       | yes
            PF3          | ESC R    | ESC R       | yes
            PF4          | ESC S    | ESC S       | no
            * (multiply) | *        | ESC ? j     | no
            + (add)      | +        | ESC ? k     | no
            , (comma)    | ,        | ESC ? l     | no
            - (minus)    | -        | ESC ? m     | no
            . (period)   | .        | ESC ? n     | yes
            / (divide)   | /        | ESC ? o     | no
            0            | 0        | ESC ? p     | yes
            1            | 1        | ESC ? q     | yes
            2            | 2        | ESC ? r     | yes
            3            | 3        | ESC ? s     | yes
            4            | 4        | ESC ? t     | yes
            5            | 5        | ESC ? u     | yes
            6            | 6        | ESC ? v     | yes
            7            | 7        | ESC ? w     | yes
            8            | 8        | ESC ? x     | yes
            9            | 9        | ESC ? y     | yes
            = (equal)    | =        | ESC ? X     | no
            -------------+----------+-------------+----------

Sun-Style Function Keys

The xterm program provides support for Sun keyboards more directly, by a
menu toggle that causes it to send Sun-style function key codes rather
than VT220.  Note, however, that the sun and VT100 emulations are not
really compatible.  For example, their wrap-margin behavior differs.

Only function keys are altered; keypad and cursor keys are the same.
The emulation responds identically.  See the xterm-sun terminfo entry
for details.


HP-Style Function Keys

Similarly, xterm can be compiled to support HP keyboards.  See the
xterm-hp terminfo entry for details.


Non-Function Keys

On a DEC terminal keyboard, some of the keys which one would expect to
see labeled as function keys had special names.  The keys actually send
character sequences as if they were the expected function keys, but the
special names are used in documentation.  Because other keyboards may
use those names, xterm maps the X key symbols which have the
corresponding names into the character sequences which the original DEC
keyboard would send.

These mappings are used for the DEC (VT220) and other keyboards:

     Label           DEC          SUN            HP         SCO
     --------------+------------+--------------+----------+----------
     Up            | SS3 A      | SS3 A        | ESC A    | CSI A
     Down          | SS3 B      | SS3 B        | ESC B    | CSI B
     Right         | SS3 C      | SS3 C        | ESC C    | CSI C
     Left          | SS3 D      | SS3 D        | ESC D    | CSI D
     Clear         | -          | -            | ESC J    | -
     Find          | CSI 1 ~    | CSI 1 z      | ESC h    | -
     Insert        | CSI 2 ~    | CSI 2 z      | ESC Q    | CSI L
     Delete        | CSI 3 ~    | CSI 3 z      | ESC P    | -
     Keypad Insert | CSI 2 ~    | CSI 2 z      | ESC Q    | CSI L
     Keypad Delete | CSI 3 ~    | CSI 3 z      | ESC P    | -
     Remove        | CSI 3 ~    | CSI 3 z      | ESC P    | -
     Select        | CSI 4 ~    | CSI 4 z      | ESC F    | -
     Prior         | CSI 5 ~    | CSI 2 1 6 z  | ESC T    | CSI I
     Next          | CSI 6 ~    | CSI 2 2 2 z  | ESC S    | CSI G
     Help          | CSI 2 8 ~  | CSI 1 9 6 z  | -        | -
     Menu          | CSI 2 9 ~  | CSI 1 9 7 z  | -        | -
     Home          | -          | CSI 2 1 4 z  | ESC h    | CSI H
     End           | -          | CSI 2 2 0 z  | ESC F    | CSI F
     Begin         | -          | CSI 2 1 8 z  | -        | CSI E
     --------------+------------+--------------+----------+----------

The Alternate Screen Buffer

XTerm maintains two screen buffers.  The Normal Screen Buffer allows you
to scroll back to view saved lines of output up to the maximum set by
the saveLines resource.  The Alternate Screen Buffer is exactly as large
as the display, contains no additional saved lines.  When the Alternate
Screen Buffer is active, you cannot scroll back to view saved lines.
XTerm provides control sequences and menu entries for switching between
the two.

Most full-screen applications use terminfo or termcap to obtain strings
used to start/stop full-screen mode, i.e., smcup and rmcup for terminfo,
or the corresponding ti and te for termcap.  The titeInhibit resource
removes the ti and te strings from the TERMCAP string which is set in
the environment for some platforms.  That is not done when xterm is
built with terminfo libraries because terminfo does not provide the
whole text of the termcap data in one piece.  It would not work for
terminfo anyway, since terminfo data is not passed in environment
variables; setting an environment variable in this manner would have no
effect on the application's ability to switch between Normal and
Alternate Screen buffers.  Instead, the newer private mode controls
(such as 1 0 4 9 ) for switching between Normal and Alternate Screen
buffers simply disable the switching.  They add other features such as
clearing the display for the same reason: to make the details of
switching independent of the application that requests the switch.


Bracketed Paste Mode

When bracketed paste mode is set, pasted text is bracketed with control
sequences so that the program can differentiate pasted text from typed-
in text.  When bracketed paste mode is set, the program will receive:
   ESC [ 2 0 0 ~ ,
followed by the pasted text, followed by
   ESC [ 2 0 1 ~ .
For background and discussion, see the FAQ:

  XTerm - bracketed-paste

Readline Modes

Several modes provide support for mouse button events in readline.
Bracketed paste is one of these readline modes, but is used more widely.

Some assumptions (particular mouse buttons) and limitations (the mouse
is clicked on the current row on the screen) apply:

2 0 0 1   If mouse button 1 is used to end or extend a selection (the
          select-end action), and if the cursor position is on the same
          row as the mouse-click, send left/right cursor control
          sequences to the host to adjust the cursor position to match
          the mouse click.

2 0 0 2   When pasting text (the insert-selection action which is
          normally bound to mouse button 2), if mouse protocol is not
          enabled, and if the cursor position is on the same row as the
          mouse-click, send left/right cursor control sequences to the
          host to adjust the cursor position to match the mouse click.

2 0 0 3   If mouse button 3 is double-clicked when ending or extending a
          selection, (the select-end action), and if the cursor position
          is on the same line as the mouse-click:

          o   Send left/right cursor control sequences to the host to
              adjust the cursor position to match the mouse click.

          o   In addition to the same row, the selection may be part of
              a wrapped line as in other xterm selections (see the
              Selection Functions section in the manual page).

          o   After adjusting the cursor position, xterm sends erase-
              characters (one for each character in the selection) to
              tell the host to delete the selected text.

2 0 0 5   When writing a selection to the host (i.e., pasting text),
          escape each character with the literal-next (Ctrl-V)
          character.

2 0 0 6   Normally when xterm writes selections to the host, it
          translates newlines to carriage returns.  This mode disables
          the translation, passing newlines literally.


Title Modes

The window- and icon-labels can be set or queried using control
sequences.  As a VT220-emulator, xterm "should" limit the character
encoding for the corresponding strings to ISO-8859-1.  Indeed, it used
to be the case (and was documented) that window titles had to be
ISO-8859-1.  This is no longer the case.  However, there are many
applications which still assume that titles are set using ISO-8859-1.
So that is the default behavior.

If xterm is running with UTF-8 encoding, it is possible to use window-
and icon-labels encoded using UTF-8.  That is because the underlying X
libraries (and many, but not all) window managers support this feature.

The utf8Title X resource setting tells xterm to disable a reconversion
of the title string back to ISO-8859-1, allowing the title strings to be
interpreted as UTF-8.  The same feature can be enabled using the title
mode control sequence described in this summary.

Separate from the ability to set the titles, xterm provides the ability
to query the titles, returning them either in ISO-8859-1 or UTF-8.  This
choice is available only while xterm is using UTF-8 encoding.

Finally, the characters sent to, or returned by a title control are less
constrained than the rest of the control sequences.  To make them more
manageable (and constrained), for use in shell scripts, xterm has an
optional feature which decodes the string from hexadecimal (for setting
titles) or for encoding the title into hexadecimal when querying the
value.


Mouse Tracking

The VT widget can be set to send the mouse position and other
information on button presses.  These modes are typically used by
editors and other full-screen applications that want to make use of the
mouse.

There are two sets of mutually exclusive modes:

o   mouse protocol

o   protocol encoding

The mouse protocols include DEC Locator mode, enabled by the DECELR CSI
Ps ; Ps '  z control sequence, and is not described here (control
sequences are summarized above).  The remaining five modes of the mouse
protocols are each enabled (or disabled) by a different parameter in the
"DECSET CSI ? Pm h " or "DECRST CSI ? Pm l " control sequence.

Manifest constants for the parameter values are defined in xcharmouse.h
as follows:

     #define SET_X10_MOUSE               9
     #define SET_VT200_MOUSE             1000
     #define SET_VT200_HIGHLIGHT_MOUSE   1001
     #define SET_BTN_EVENT_MOUSE         1002
     #define SET_ANY_EVENT_MOUSE         1003

     #define SET_FOCUS_EVENT_MOUSE       1004

     #define SET_ALTERNATE_SCROLL        1007

     #define SET_EXT_MODE_MOUSE          1005
     #define SET_SGR_EXT_MODE_MOUSE      1006
     #define SET_URXVT_EXT_MODE_MOUSE    1015
     #define SET_PIXEL_POSITION_MOUSE    1016

The motion reporting modes are strictly xterm extensions, and are not
part of any standard, though they are analogous to the DEC VT200 DECELR
locator reports.

Normally, parameters (such as pointer position and button number) for
all mouse tracking escape sequences generated by xterm encode numeric
parameters in a single character as value+32.  For example, !  specifies
the value 1.  The upper left character position on the terminal is
denoted as 1,1.  This scheme dates back to X10, though the normal mouse-
tracking (from X11) is more elaborate.


X10 compatibility mode

X10 compatibility mode sends an escape sequence only on button press,
encoding the location and the mouse button pressed.  It is enabled by
specifying parameter 9 to DECSET.  On button press, xterm sends CSI M
CbCxCy (6 characters).

o   Cb is button-1, where button is 1, 2 or 3.

o   Cx and Cy are the x and y coordinates of the mouse when the button
    was pressed.


Normal tracking mode

Normal tracking mode sends an escape sequence on both button press and
release.  Modifier key (shift, ctrl, meta) information is also sent.  It
is enabled by specifying parameter 1000 to DECSET.  On button press or
release, xterm sends CSI M CbCxCy.

o   The low two bits of Cb encode button information:

              0=MB1 pressed,
              1=MB2 pressed,
              2=MB3 pressed, and
              3=release.

o   The next three bits encode the modifiers which were down when the
    button was pressed and are added together:

              4=Shift,
              8=Meta, and
              16=Control.

    The shift and control modifiers are normally irrelevant because
    xterm uses the control modifier with mouse for popup menus, and the
    shift modifier is used in the default translations for button
    events.

    There is no predefined meta modifier.  XTerm checks first if the
    keysyms listed in the predefined modifiers include Meta_L or Meta_R.
    If found, xterm uses that modifier for meta.  Next, it tries Alt_L
    or Alt_R.  If none of those are found, xterm uses the mod1 modifier,
    This is not necessarily the "Meta" key according to xmodmap(1).

o   Cx and Cy are the x and y coordinates of the mouse event, encoded as
    in X10 mode.


Wheel mice

Wheel mice may return buttons 4 and 5.  Those buttons are represented by
the same event codes as buttons 1 and 2 respectively, except that 64 is
added to the event code.  Release events for the wheel buttons are not
reported.

By default, the wheel mouse events (buttons 4 and 5) are translated to
scroll-back and scroll-forw actions, respectively.  Those actions
normally scroll the whole window, as if the scrollbar was used.

However if Alternate Scroll mode is set, then cursor up/down controls
are sent when the terminal is displaying the Alternate Screen Buffer.
The initial state of Alternate Scroll mode is set using the
alternateScroll resource.


Other buttons

Some wheel mice can send additional button events, e.g., by tilting the
scroll wheel left and right.

Additional buttons are encoded like the wheel mice,

o   by adding 64 (for buttons 6 and 7), or

o   by adding 128 (for buttons 8 through 11).

Past button 11, the encoding is ambiguous because the same code may
correspond to different button/modifier combinations.

It is not possible to use these buttons (6-11) in xterm's translations
resource because their names are not in the X Toolkit's symbol table.
However, applications can check for the reports, e.g., button 7 (left)
and button 6 (right) with a Logitech mouse.


Highlight tracking

Mouse highlight tracking notifies a program of a button press, receives
a range of lines from the program, highlights the region covered by the
mouse within that range until button release, and then sends the program
the release coordinates.  It is enabled by specifying parameter 1001 to
DECSET.  Highlighting is performed only for button 1, though other
button events can be received.

Warning: this mode requires a cooperating program, else xterm will hang.

On button press, the same information as for normal tracking is
generated; xterm then waits for the program to send mouse tracking
information.  All X events are ignored until the proper escape sequence
is received from the pty:
CSI Ps ; Ps ; Ps ; Ps ; Ps T

The parameters are func, startx, starty, firstrow, and lastrow:

o   func is non-zero to initiate highlight tracking and zero to abort.

o   startx and starty give the starting x and y location for the
    highlighted region.

o   The ending location tracks the mouse, but will never be above row
    firstrow and will always be above row lastrow.  (The top of the
    screen is row 1.)

When the button is released, xterm reports the ending position one of
two ways:

o   if the start and end coordinates are the same locations:

    CSI t CxCy

o   otherwise:

    CSI T CxCyCxCyCxCy

The parameters are startx, starty, endx, endy, mousex, and mousey:

o   startx, starty, endx, and endy give the starting and ending
    character positions of the region.

o   mousex and mousey give the location of the mouse at button up, which
    may not be over a character.


Button-event tracking

Button-event tracking is essentially the same as normal tracking, but
xterm also reports button-motion events.  Motion events are reported
only if the mouse pointer has moved to a different character cell.  It
is enabled by specifying parameter 1002 to DECSET.  On button press or
release, xterm sends the same codes used by normal tracking mode.

o   On button-motion events, xterm adds 32 to the event code (the third
    character, Cb).

o   The other bits of the event code specify button and modifier keys as
    in normal mode.  For example, motion into cell x,y with button 1
    down is reported as

    CSI M @ CxCy

    ( @  = 32 + 0 (button 1) + 32 (motion indicator) ).  Similarly,
    motion with button 3 down is reported as

    CSI M B CxCy

    ( B  = 32 + 2 (button 3) + 32 (motion indicator) ).


Any-event tracking

Any-event mode is the same as button-event mode, except that all motion
events are reported, even if no mouse button is down.  It is enabled by
specifying 1003 to DECSET.


FocusIn/FocusOut

FocusIn/FocusOut can be combined with any of the mouse events since it
uses a different protocol.  When set, it causes xterm to send CSI I
when the terminal gains focus, and CSI O  when it loses focus.


Extended coordinates

The original X10 mouse protocol limits the Cx and Cy ordinates to 223
(=255 - 32).  XTerm supports more than one scheme for extending this
range, by changing the protocol encoding:

UTF-8 (1005)
          This enables UTF-8 encoding for Cx and Cy under all tracking
          modes, expanding the maximum encodable position from 223 to
          2015.  For positions less than 95, the resulting output is
          identical under both modes.  Under extended mouse mode,
          positions greater than 95 generate "extra" bytes which will
          confuse applications which do not treat their input as a UTF-8
          stream.  Likewise, Cb will be UTF-8 encoded, to reduce
          confusion with wheel mouse events.

          Under normal mouse mode, positions outside (160,94) result in
          byte pairs which can be interpreted as a single UTF-8
          character; applications which do treat their input as UTF-8
          will almost certainly be confused unless extended mouse mode
          is active.

          This scheme has the drawback that the encoded coordinates will
          not pass through luit(1) unchanged, e.g., for locales using
          non-UTF-8 encoding.

SGR (1006)
          The normal mouse response is altered to use

          o   CSI < followed by semicolon-separated

          o   encoded button value,

          o   Px and Py ordinates and

          o   a final character which is M  for button press and m  for
              button release.

          The encoded button value in this case does not add 32 since
          that was useful only in the X10 scheme for ensuring that the
          byte containing the button value is a printable code.

          o   The modifiers are encoded in the same way.

          o   A different final character is used for button release to
              resolve the X10 ambiguity regarding which button was
              released.

          The highlight tracking responses are also modified to an SGR-
          like format, using the same SGR-style scheme and button-
          encodings.

URXVT (1015)
          The normal mouse response is altered to use

          o   CSI followed by semicolon-separated

          o   encoded button value,

          o   the Px and Py ordinates and final character M .

          This uses the same button encoding as X10, but printing it as
          a decimal integer rather than as a single byte.

          However, CSI M  can be mistaken for DL (delete lines), while
          the highlight tracking CSI T  can be mistaken for SD (scroll
          down), and the Window manipulation controls.  For these
          reasons, the 1015 control is not recommended; it is not an
          improvement over 1006.

SGR-Pixels (1016)
          Use the same mouse response format as the 1006 control, but
          report position in pixels rather than character cells.


Graphics


Sixel Graphics

If xterm is configured as VT240, VT241, VT330, VT340 or VT382 using the
decTerminalID or decGraphicsID resource, it supports Sixel Graphics
controls, a paletted bitmap graphics system using sets of six vertical
pixels as the basic element.

CSI Ps c  Send Device Attributes (Primary DA), DEC graphics terminals,
          xterm.  xterm responds to Send Device Attributes (Primary DA)
          with these additional codes:
            Ps = 4  -> Sixel graphics.

CSI ? Pm h
          Set Mode (with corresponding Reset Mode CSI ? Pm l ):
            Ps = 8 0  -> Sixel Display Mode (DECSDM), VT330, VT340,
          VT382.
            Ps = 1 0 7 0  -> use private color registers for each
          graphic, xterm.
            Ps = 8 4 5 2  -> Sixel scrolling leaves cursor to right of
          graphic, RLogin, xterm.

DCS Pa ; Pb ; Ph q  Ps..Ps ST
          Send SIXEL image, DEC graphics terminals, VT330, VT340, VT382.
          See:

             VT330/VT340 Programmer Reference Manual Volume 2:
             Graphics Programming
             Chapter 14 Graphics Programming

          The sixel data device control string has three positional
          parameters, following the q  with sixel data.
            Pa -> pixel aspect ratio
            Pb -> background color option
            Ph -> horizontal grid size (ignored).
            Ps -> sixel data


ReGIS Graphics

If xterm is configured as VT125, VT240, VT241, VT330 or VT340 using the
decTerminalID or decGraphicsID resource, it supports Remote Graphic
Instruction Set, a graphics description language.

CSI Ps c  Send Device Attributes (Primary DA), DEC graphics terminals,
          xterm.  xterm responds to Send Device Attributes (Primary DA)
          with these additional codes:
            Ps = 3  -> ReGIS graphics.

CSI ? Pm h
          Set Mode, xterm.  xterm has these additional private Set Mode
          values:
            Ps = 1 0 7 0  -> use private color registers for each
          graphic.

DCS Pm p Pr..Pr ST
          Enter or exit ReGIS, VT300, xterm.  See:

             VT330/VT340 Programmer Reference Manual Volume 2:
             Graphics Programming
             Chapter 1 Introduction to ReGIS

          The ReGIS data device control string has one positional
          parameter with four possible values:
            Pm = 0 -> resume command, use fullscreen mode.
            Pm = 1 -> start new command, use fullscreen mode.
            Pm = 2 -> resume command, use command display mode.
            Pm = 3 -> start new command, use command display mode.

A few of the VT330/VT340 private modes conflict with xterm.  Codes 4 0
to 4 7  were first used by xterm in X10R4 (December 1986).  While X11R1
xterm dropped codes 4 1  and 4 2 , the remaining ones are still used.
The VT330/VT340 introduced in April 1987 uses 4 4  to 4 7  for color
graphics printing controls.  When configured for ReGIS, xterm uses the
VT330/VT340 interpretation of these private modes.


Non-VT100 Modes


Tektronix 4014 Mode

Most of these sequences are standard Tektronix 4014 control sequences.
Graph mode supports the 12-bit addressing of the Tektronix 4014.  The
major features missing are the write-through and defocused modes.  This
document does not describe the commands used in the various Tektronix
plotting modes but does describe the commands to switch modes.

Some of the sequences are specific to xterm.  The Tektronix emulation
was added in X10R4 (1986).  The VT240, introduced two years earlier,
also supported Tektronix 4010/4014.  Unlike xterm, the VT240
documentation implies (there is an obvious error in section 6.9
"Entering and Exiting 4010/4014 Mode") that exiting back to ANSI mode is
done by resetting private mode 3 8  (DECTEK) rather than ESC ETX .  A
real Tektronix 4014 would not respond to either.

BEL       Bell (Ctrl-G).

BS        Backspace (Ctrl-H).

TAB       Horizontal Tab (Ctrl-I).

LF        Line Feed or New Line (Ctrl-J).

VT        Cursor up (Ctrl-K).

FF        Form Feed or New Page (Ctrl-L).

CR        Carriage Return (Ctrl-M).

ESC ETX   Switch to VT100 Mode (ESC  Ctrl-C).

ESC ENQ   Return Terminal Status (ESC  Ctrl-E).

ESC FF    PAGE (Clear Screen) (ESC  Ctrl-L).

ESC SO    Begin 4015 APL mode (ESC  Ctrl-N).  This is ignored by xterm.

ESC SI    End 4015 APL mode (ESC  Ctrl-O).  This is ignored by xterm.

ESC ETB   COPY (Save Tektronix Codes to file COPYyyyy-mm-dd.hh:mm:ss).
            ETB  (end transmission block) is the same as Ctrl-W.

ESC CAN   Bypass Condition (ESC  Ctrl-X).

ESC SUB   GIN mode (ESC  Ctrl-Z).

ESC FS    Special Point Plot Mode (ESC  Ctrl-\).

ESC 8     Select Large Character Set.

ESC 9     Select #2 Character Set.

ESC :     Select #3 Character Set.

ESC ;     Select Small Character Set.

OSC Ps ; Pt BEL
          Set Text Parameters of VT window.
            Ps = 0  -> Change Icon Name and Window Title to Pt.
            Ps = 1  -> Change Icon Name to Pt.
            Ps = 2  -> Change Window Title to Pt.
            Ps = 4 6  -> Change Log File to Pt.  This is normally
          disabled by a compile-time option.

ESC `     Normal Z Axis and Normal (solid) Vectors.

ESC a     Normal Z Axis and Dotted Line Vectors.

ESC b     Normal Z Axis and Dot-Dashed Vectors.

ESC c     Normal Z Axis and Short-Dashed Vectors.

ESC d     Normal Z Axis and Long-Dashed Vectors.

ESC h     Defocused Z Axis and Normal (solid) Vectors.

ESC i     Defocused Z Axis and Dotted Line Vectors.

ESC j     Defocused Z Axis and Dot-Dashed Vectors.

ESC k     Defocused Z Axis and Short-Dashed Vectors.

ESC l     Defocused Z Axis and Long-Dashed Vectors.

ESC p     Write-Thru Mode and Normal (solid) Vectors.

ESC q     Write-Thru Mode and Dotted Line Vectors.

ESC r     Write-Thru Mode and Dot-Dashed Vectors.

ESC s     Write-Thru Mode and Short-Dashed Vectors.

ESC t     Write-Thru Mode and Long-Dashed Vectors.

FS        Point Plot Mode (Ctrl-\).

GS        Graph Mode (Ctrl-]).

RS        Incremental Plot Mode (Ctrl-^ ).

US        Alpha Mode (Ctrl-_).


VT52 Mode

Parameters for cursor movement are at the end of the ESC Y  escape
sequence.  Each ordinate is encoded in a single character as value+32.
For example, !  is 1.  The screen coordinate system is 0-based.

ESC <     Exit VT52 mode (Enter VT100 mode).

ESC =     Enter alternate keypad mode.

ESC >     Exit alternate keypad mode.

ESC A     Cursor up.

ESC B     Cursor down.

ESC C     Cursor right.

ESC D     Cursor left.

ESC F     Enter graphics mode.

ESC G     Exit graphics mode.

ESC H     Move the cursor to the home position.

ESC I     Reverse line feed.

ESC J     Erase from the cursor to the end of the screen.

ESC K     Erase from the cursor to the end of the line.

ESC Y Ps Ps
          Move the cursor to given row and column.

ESC Z     Identify.
            -> ESC  /  Z  ("I am a VT52 emulated by VT100.").
          or
            -> ESC  /  K  ("I am a VT52.").
          depending on whether xterm is started as a VT52 by setting the
          decTerminalID resource to "52" or not.


Further reading


Technical manuals

Manuals for hardware terminals are more readily available than
similarly-detailed documentation for terminal emulators such as aixterm,
shelltool, dtterm.

However long, the technical manuals have problems:

o   DEC's manuals did not provide a comprehensive comparison of the
    features in different model.

    Host Interface Functions Checklist by Peter Sichel (January 12,
    1994) is helpful.  This spreadsheet is useful for noting which model
    introduced a given feature (although there are a few apparent errors
    such as the DECRQSS feature cited for VT320 whereas the technical
    manual omits it).

o   Sometimes the manuals disagree.  For example, DEC's standard
    document (DEC STD 070) for terminals says that DECSCL performs a
    soft reset (DECSTR), while the VT420 manual says it does a hard
    reset (RIS).

o   Sometimes the manuals are simply incorrect.  For example, testing a
    DEC VT420 in 1996 showed that the documented code for a valid or
    invalid response to DECRQSS was reversed.

    The VT420 test results were incorporated into the vttest program.
    At the time, DEC STD 070 was not available, but it also agrees with
    vttest.  Later, documentation for the DEC VT525 was shown to have
    the same flaw.

o   The VT330/VT340 reference manual for graphics programming documents
    sixel graphics in some detail in chapter 14.  Overlooked in the
    first edition, the second edition mentions Sixel Scrolling.  The
    VT382 Kanji and Thai manuals provide less information, about sixel
    graphics, but do mention DECSDM.  They differ in their comment about
    the private mode DECSDM (CSI ? 8 0 h ), which each manual agrees
    should set the Sixel Scrolling feature.  The VT330/VT340 graphics
    programming manual (second edition, March 1988) says

        When sixel display mode is set, the Sixel Scrolling feature is
        enabled.
        When sixel display mode is reset, the Sixel Scrolling feature is
        disabled.

    while the VT382 Kanji manual (page 6-6, undated) says

        Disable sixel scroll

    and the VT382 Thai manual (page C-30, August 1989) says

        No Sixel scrolling

    The standard (DEC STD 070) in chapter 9 (August 3, 1990) states on
    page 17 that video devices will scroll when advancing the Sixel
    active position past the bottom margin, but on page 19, in the
    section on deviations, states that VT125 and VT240 did not scroll in
    this situation.  The standard does not mention VT330/VT340 or VT382.
    Nor does it document DECSDM.

o   Not all details are clear even in DEC STD 070 (which is more than
    twice the length of the VT520 programmer's reference manual, and
    almost three times longer than the VT420 reference manual).
    However, as an internal standards document, DEC STD 070 is more
    likely to describe the actual behavior of DEC's terminals than the
    more polished user's guides.

That said, here are technical manuals which have been used in developing
xterm.  Not all were available initially.  In August 1996 for instance,
the technical references were limited to EK-VT220-HR-002 and EK-
VT420-UG.002.  Shortly after, Richard Shuford sent a copy of EK-VT3XX-
TP-001.  Still later (beginning in 2003), Paul Williams' vt100.net site
provided EK-VT102-UG-003, EK-VT220-RM-002, EK-VT420-RM-002, EK-VT520-RM
A01, EK-VT100-TM-003, and EK-VT102-UG-003.  In addition, several
documents were found on the bitsavers site.

o   DECscope User's Manual.
    Digital Equipment Corporation (EK-VT5X-OP-001 1975).

o   VT100 Series Video Terminal Technical Manual.
    Digital Equipment Corporation (EK-VT100-TM-003, July 1982).

o   VT100 User Guide.
    Digital Equipment Corporation (EK-VT100-UG-003, June 1981).

o   VT102 User Guide.
    Digital Equipment Corporation (EK-VT102-UG-003, February 1982).

o   VT220 Programmer Pocket Guide.
    Digital Equipment Corporation (EK-VT220-HR-002, July 1984).

o   VT220 Programmer Reference Manual.
    Digital Equipment Corporation (EK-VT220-RM-002, August 1984).

o   VT240 Programmer Reference Manual.
    Digital Equipment Corporation (EK-VT240-RM-002, October 1984).

o   VT330/VT340 Programmer Reference Manual
    Volume 1: Text Programming.
    Digital Equipment Corporation (EK-VT3XX-TP-001, March 1987).

o   VT330/VT340 Programmer Reference Manual
    Volume 2: Graphics Programming.
    Digital Equipment Corporation (EK-VT3XX-GP-001, March 1987).

o   VT330/VT340 Programmer Reference Manual
    Volume 2: Graphics Programming.
    Digital Equipment Corporation (EK-VT3XX-GP-002, May 1988).

o   VT382 Kanji Display Terminal
    Programmer Reference Manual.
    Digital Equipment Corporation (EK-VT382-RM-001, undated).

o   VT382 Thai Display Terminal
    Installing and Using Manual.
    Digital Equipment Corporation (EK-VT38T-UG-001, August 1989).

o   Installing and Using
    The VT420 Video Terminal
    (North American Model).
    Digital Equipment Corporation (EK-VT420-UG.002, February 1990).

o   VT420 Programmer Reference Manual.
    Digital Equipment Corporation (EK-VT420-RM-002, February 1992).

o   VT510 Video Terminal
    Programmer Information.
    Digital Equipment Corporation (EK-VT510-RM B01, November 1993).

o   VT520/VT525 Video Terminal
    Programmer Information.
    Digital Equipment Corporation (EK-VT520-RM A01, July 1994).

o   Digital ANSI-Compliant Printing Protocol
    Level 2 Programming Reference Manual
    Digital Equipment Corporation (EK-PPLV2-PM B01, August 1994).

o   Disk Operating System
    DOS 2.00
    Microsoft, Inc.
    First edition, January 1983.

o   4014 and 4014-1 Computer Display Terminal
    User's Manual.
    Tektronix, Inc.  (070-1647-00, November 1979).


Standards

The DEC terminal family (VT100 through VT525) is upward-compatible,
using standards plus extensions, e.g., "private modes".  Not all
commonly-used features are standard.  For example, scrolling regions are
not found in ECMA-48.  On the other hand, ECMA-48 was not intended to be
all-encompassing.  Quoting from the second edition:

    Full conformance to a standard means that all its requirements are
    met.  For such conformance to be unique the standard must contain no
    options.  This is typically the case for hardware standards, for
    instance Standard ECMA-10 for data interchange on punched tapes.

    This Standard ECMA-48 is of a different nature and as a result, it
    is only practicable to envisage limited conformance to it, as
    defined hereunder.

    This Standard addresses a whole class of devices which can vary
    greatly from each other depending on the application for which a
    device has been specifically designed.  Obviously, a product which
    implements all facilities described in this standard - thus being in
    "full conformance" with it - whilst theoretically possible, would be
    technically and economically unthinkable.

Again, it is possible to find discrepancies in the standards:

o   The printed ECMA-48 5th edition (1991) and the first PDF produced
    for that edition (April 1998) state that SD (scroll down) ends with
    05/14, i.e., ^ , which disagrees with DEC's VT420 hardware
    implementation and DEC's manuals which use 05/04 T .  (A few other
    terminals such as AT&T 5620 and IBM 5151 also used 05/04, but the
    documentation and dates are lacking).

    ECMA created a new PDF in April 2003 which changed that detail to
    use T , and later in 2008 provided PDFs of the earlier editions
    which used T .

o   The first edition of ECMA-48 has not been available, to compare.  As
    of September 2021, ECMA's website provides a copy of ECMA-46 in its
    place.

    Earlier versions of ISO 6429 have never been available.  The first
    three editions of ISO 6429 were issued in 1983, 1988, and 1992.

o   ANSI X3.64-1979 does not list color as a feature of the SGR sequence
    (page 49).

    In Appendix A, it mentions ECMA-48:

        (8) This document represents a coordinated effort to develop a
        single technical standard in the United States and Europe (see
        ECMA-48 standard entitled Additional Controls for Character
        Imaging Input/Output Devices).

    Appendix H clarifies the relationship between these documents
    somewhat though it confuses the first two editions of ECMA-48.  The
    typo for "work" versus "owkr" appears in the original document:

        ANSI X3.64-1979, and ECMA-48, Additional Controls for Character-
        Imaging I/O Devices, were developed in parallel, with close
        liaison.  ISO DP 6429, Additional Control Functions for
        Character-Imaging Devices, was developed as a synthesis of X3.64
        and ECMA-48.  During this process, some control functions as
        well as additional selective parameters were added.  Except for
        point 1 below, X3.64 is a subset of ISO 6429.  Although the two
        standards use different language, the intent is that the subset
        is technically identical.  X3.64 was balloted and forwarded
        prior to the final resolution of ISO 6429 and does not
        incorporate the owkr of IS0/TC97/SC2 in completing ISO 6429.
        Revision of X3.64 will attempt to incorporate those elements and
        assumptions of X3.64.

    ANSI X3.64 goes on to say that the SGR codes 8, 30-47 are in ISO
    6429.  It includes 38 and 39, but omits 48 and 49.  At the time, ISO
    6429's first edition was still four years in the future.  The writer
    probably was referring to the ongoing process of making ECMA-48
    second edition into the ISO standard.

o   The VT320, VT420, VT520 manuals claim that DECSCL does a hard reset
    (RIS).

    Both the VT220 manual and DEC STD 070 (which documents levels 1-4 in
    detail) state that it is a soft reset, e.g., DECSTR.

Here are the relevant standards:

o   Additional Controls for Use with American National Standard Code for
    Information Interchange, ANSI X3.64-1979
    FIPS Publication 86. July 18, 1979.
    American National Standards Institute, Inc.

o   ECMA-35: Character Code Structure and Extension Techniques
    (6th Edition, December 1994).

o   ECMA-43: 8-bit Coded Character Set Structure and Rules
    (3rd Edition, December 1991).

o   ECMA-48: Control Functions for Coded Character Sets
    (5th Edition, June 1991).

o   DEC STD 070 Video Systems Reference Manual.
    Digital Equipment Corporation (A-MN-ELSM070-00-0000 Rev H, December
    3, 1991).


Miscellaneous

A few hardware terminals survived into the 1990s only as terminal
emulators.  Documentation for these and other terminal emulators which
have influenced xterm are generally available only in less-accessible
and less-detailed manual pages.

o   XTerm supports control sequences for manipulating its window which
    were implemented by Sun's shelltool program.  This was part of
    SunView (SunOS 3.0, 1986).  The change-notes for xterm's resize
    program in X10.4 (1986) mention its use of these "Sun tty emulation
    escape sequences" for resizing the window.  The X10.4 xterm program
    recognized these sequences for resizing the terminal, except for the
    iconify/deiconify pair.  SunView also introduced the SIGWINCH
    signal, used by the X10.4 xterm and mentioned in its CHANGES file:

        The window size is passed to the operating system via TIOCSWINSZ
        (4.3) or TIOCSSIZE (sun).  A SIGWINCH signal is sent if the
        vtXXX window is resized.

    While support for the Sun control-sequences remained in resize, the
    next release of xterm (X11R1 in 1987) omitted the code for
    interpreting them.

    Later, the SunView program was adapted for the OPEN LOOK environment
    introduced 1988-1990.

    Still later, in 1995, OPEN LOOK was abandoned in favor of CDE.  The
    CDE terminal emulator dtterm implemented those controls, with a
    couple of additions.

    Starting in July 1996, xterm re-implemented those control sequences
    (based on the dtterm manual pages) and further extended the group of
    window controls.

    There were two sets of controls (CSI Ps [ ; Pm ; Pm ] t , and OSC Ps
    text ST ) implemented by shelltool, documented in appendix E of both
    PHIGS Programming Manual (1992), and the unpublished X Window System
    User's Guide (OPEN LOOK Edition) (1995).  The CDE program kept
    those, and added a few new ones.

    Code         Sun   CDE   XTerm   Description
    -----------+-----+-----+-------+---------------------------------
    CSI 1 t    | yes | yes |  yes  | de-iconify
    CSI 2 t    | yes | yes |  yes  | iconify
    CSI 3 t    | yes | yes |  yes  | move window to pixel-position
    CSI 4 t    | yes | yes |  yes  | resize window in pixels
    CSI 5 t    | yes | yes |  yes  | raise window to front of stack
    CSI 6 t    | yes | yes |  yes  | raise window to back of stack
    CSI 7 t    | yes | yes |  yes  | refresh window
    CSI 8 t    | yes | yes |  yes  | resize window in chars
    CSI 9 t    |  -  |  -  |  yes  | maximize/unmaximize window
    CSI 1 0 t  |  -  |  -  |  yes  | to/from full-screen
    CSI 1 1 t  | yes | yes |  yes  | report if window is iconified
    CSI 1 2 t  |  -  |  -  |   -   | -
    CSI 1 3 t  | yes | yes |  yes  | report window position
    CSI 1 4 t  | yes | yes |  yes  | report window size in pixels
    CSI 1 5 t  |  -  |  -  |  yes  | report screen size in pixels
    CSI 1 6 t  |  -  |  -  |  yes  | report character cell in pixels
    CSI 1 7 t  |  -  |  -  |   -   | -
    CSI 1 8 t  | yes | yes |  yes  | report window size in chars
    CSI 1 9 t  |  -  |  -  |  yes  | report screen size in chars
    CSI 2 0 t  |  -  | yes |  yes  | report icon label
    CSI 2 1 t  |  -  | yes |  yes  | report window title
    CSI 2 2 t  |  -  |  -  |  yes  | save window/icon title
    CSI 2 3 t  |  -  |  -  |  yes  | restore window/icon title
    CSI 2 4 t  |  -  |  -  |  yes  | resize window (DECSLPP)
    OSC 0 ST   |  -  | yes |  yes  | set window and icon title
    OSC 1 ST   |  -  | yes |  yes  | set icon label
    OSC 2 ST   |  -  | yes |  yes  | set window title
    OSC 3 ST   |  -  | n/a |  yes  | set X server property
    OSC I ST   | yes | yes |  yes  | set icon to file
    OSC l ST   | yes | yes |  yes  | set window title
    OSC L ST   | yes | yes |  yes  | set icon label
    -----------+-----+-----+-------+---------------------------------

    Besides the Sun-derived OSC controls for setting window title and
    icon label, dtterm also supported the xterm controls for the same
    feature.

    The CDE source was unavailable for inspection until 2012, so that
    clarification of the details of the window operations relied upon
    vttest.  However, the manual page for the control sequences (i.e.,
    dtterm(5) in the file formats section) was readily available.  DEC
    adapted the control sequences for setting the window and icon labels
    in the VT525.  In doing so, DEC's VT520/VT525 manual changed the
    letter l to a number 1, and added a parameter 2 before the l/L (or
    1/L) code used to distinguish the window and icon labels.

o   The SCOSC/SCORC control sequences for saving/restoring the cursor
    and for saving/restoring "DEC Private Mode Values" (XTSAVE and
    XTRESTORE) may appear to be related (since the "save" controls both
    end with s ), but that is coincidental.  The latter was introduced
    in X10.4 (December 1986):

        Most Dec Private mode settings can be saved away internally
        using \E[?ns, where n is the same number to set or reset the Dec
        Private mode.  The mode can be restored using \E[?nr.  This can
        be used in termcap for vi(1), for example, to turn off saving of
        lines, but restore whatever the original state was on exit.

    while  the  SCOSC/SCORC  pair  was  added  in  1995  by XFree86 (and
    documented long afterwards).

    The SCO  ANSI  console  terminal  descriptions  did  not  use  these
    controls  (they  used the VT100-compatible SC/RC pair).  SCOSC/SCORC
    were an artifact of DOS 2.00 (January 1983), by Microsoft and  later
    supported by SCO and other vendors.

    The  SCOSC/SCORC pair is considered a private mode because the final
    characters (s  and u ) fall in the range from "`" to "~" (octal 0140
    to octal 0176).  Other private control sequences can be  constructed
    by using octets 074 to 077 (characters "<", "=", ">", or "?") at the
    beginning  of  the  parameter  string.   The  XTSAVE  and  XTRESTORE
    controls use "?") in this manner.

    Because  the  XTSAVE  and  XTRESTORE  controls  are  private,  other
    terminals  may  behave differently.  For example, DEC (a contributor
    to the early xterm as well as a manufacturer of terminals)  used  an
    incompatible  private control in one of its terminals more than five
    years later (for the VT420 PCTerm, announced in February 1992).

    In that model of the VT420, CSI ? Pm ; Pc  r  selects  the  PC  TERM
    emulation  mode.  When this mode is enabled, the keyboard sends scan
    codes rather than characters (analogous to X keyboard events).   The
    first  parameter of this private control enables or disables PC TERM
    mode, while the second selects a character set.  An ambiguity arises
    if an application omits the second parameter.  In that special case,
    it cannot be distinguished from XTRESTORE.  DEC did  not  take  this
    into account when designing the feature.

    If  there  were  potential  users, xterm could accommodate this by a
    resource setting.  In retrospect (thirty years  later),  there  have
    been  no  uses  of  PC TERM, while the XTRESTORE feature is still in
    use.

o   The aixterm manual page gives the format of the control sequence for
    foreground and background colors 8-15, but  does  not  specify  what
    those  colors  are.  That is implied by the description's mention of
    HFT:

        The aixterm command provides a standard terminal type for
        programs that do not interact directly with Enhanced X-Windows.
        This command provides an emulation for a VT102 terminal or a
        high function terminal (HFT).  The VT102 mode is activated by
        the -v flag.

    Unlike xterm, there are no resource names for the 16 colors, leaving
    the reader to assume that the mapping is  hard-coded.   The  control
    sequences  for  colors 8-15 are not specified by ECMA-48, but rather
    (as done in other instances by xterm) chosen to  not  conflict  with
    current or future standards.
