<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!--
  Licensed to the Apache Software Foundation (ASF) under one or more
  contributor license agreements.  See the NOTICE file distributed with
  this work for additional information regarding copyright ownership.
  The ASF licenses this file to You under the Apache License, Version 2.0
  (the "License"); you may not use this file except in compliance with
  the License.  You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
-->
<!-- $Id$ -->
<!DOCTYPE document PUBLIC "-//APACHE//DTD Documentation V2.0//EN" "document-v20.dtd">
<document>
  <header>
    <title>Apache™ FOP: Complex Scripts</title>
  </header>
  <body>
    <section id="overview">
      <title>Overview</title>
      <p>
        This page describes the
        <link href="http://en.wikipedia.org/wiki/Complex_scripts">complex scripts</link>
        features of Apache™ FOP, which include:
      </p>
      <ul>
        <li>Support for languages written with right-to-left scripts, such as Arabic and Hebrew scripts.</li>
        <li>Support for languages written with South Asian and Southeast Asian scripts, such as Devanagari,
          Khmer, Tamil, Thai, and others.</li>
        <li>Support for advanced substitution, reordering, and positioning of glyphs according to language
          and script sensitive rules.</li>
        <li>Support for advanced number to string formatting.</li>
      </ul>
    </section>
    <section>
      <title>Disabling complex scripts</title>
      <p>Complex script features are enabled by default. If some application of FOP does not
         require this support, then it can be disabled in three ways:</p>
      <ol>
        <li>
          <strong>Command line:</strong> The command line option <code>-nocs</code> turns off complex script
          features: <code>fop -nocs -fo mydocument.fo -pdf mydocument.pdf</code>            
        </li>
        <li>
          <strong>Embedding:</strong> <code>userAgent.setComplexScriptFeaturesEnabled(false);</code>
        </li>
        <li>
          <strong>Optional setting in fop.xconf file:</strong>
          <pre>
&lt;fop version="1.0"&gt;
  &lt;complex-scripts disabled="true"/&gt;
  ...
&lt;/fop&gt;
          </pre>
        </li>
      </ol>
      <p>
        When complex scripts features are enabled, additional information related to bidirectional
        level resolution, the association between characters and glyphs, and glyph position adjustments
        are added to the internal, parsed representation of the XSL-FO tree and its corresponding
        formatted area tree. This additional information will somewhat increase the memory requirements for
        processing documents that use these features.
      </p>
      <note>A document author need not make explicit use of any complex scripts feature in order
        for this additional information to be created. For example, if the author makes use of a font
        that contains OpenType GSUB and/or GPOS tables, then those tables will be automatically used
        unless complex scripts features are disabled.</note>
    </section>
    <section id="source">
      <title>Changes to your XSL-FO input files</title>
      <p>
        In most circumstances, XSL-FO content does not need to change in order to make use of
        complex scripts features; however, in certain contexts, fully automatic processing is not
        sufficient. In these cases, an author may make use of the following XSL-FO constructs:
      </p>
      <ul>
        <li>The <link href="http://www.w3.org/TR/2006/REC-xsl11-20061205/#script"><code>script</code></link> property.</li>
        <li>The <link href="http://www.w3.org/TR/2006/REC-xsl11-20061205/#language"><code>language</code></link> property.</li>
        <li>The <link href="http://www.w3.org/TR/2006/REC-xsl11-20061205/#writing-mode"><code>writing-mode</code></link> property.</li>
        <li>The number to string conversion properties:
          <link href="http://www.w3.org/TR/2006/REC-xsl11-20061205/#format"><code>format</code></link>,
          <link href="http://www.w3.org/TR/2006/REC-xsl11-20061205/#grouping-separator"><code>grouping-separator</code></link>,
          <link href="http://www.w3.org/TR/2006/REC-xsl11-20061205/#grouping-size"><code>grouping-size</code></link>,
          <link href="http://www.w3.org/TR/2006/REC-xsl11-20061205/#letter-value"><code>letter-value</code></link>,
          and <code>fox:number-conversion-features</code>.</li>
        <li>The <link href="http://www.w3.org/TR/2006/REC-xsl11-20061205/#fo_bidi-override"><code>fo:bidi-override</code></link> element.</li>
        <li>Explicit bidirectional control characters: U+200E LRM, U+200F RLM, U+202A LRE,
          U+202B RLE, U+202C PDF, U+202D LRO, U+202E RLO.</li>
        <li>Explicit join control characters: U+200C ZWNJ and U+200D ZWJ.</li>
      </ul>
    </section>
    <section id="details">
      <title>Authoring Details</title>
      <p>The complex scripts related effects of the above enumerated XSL-FO constructs are more
        fully described in the following sub-sections.</p>
      <section id="script_property">
        <title>Script Property</title>
        <p>In order to apply font specific complex script features, it is necessary to know
          the script that applies to the text undergoing layout processing. This script is determined
          using the following algorithm:
        </p>
        <ol>
          <li>If the FO element that governs the text specifies a
            <link href="http://www.w3.org/TR/2006/REC-xsl11-20061205/#script"><code>script</code></link>
            property and its value is not the empty string or <code>"auto"</code>, then that script is used.</li>
          <li>Otherwise, the dominant script of the text is determined automatically by finding the
            script whose constituent characters appear most frequently in the text.</li>
        </ol>
        <p>In case the automatic algorithm does not produce the desired results, an author may
          explicitly specify a <code>script</code> property with the desired script. If specified,
          it must be one of the four-letter script code specified in
          <link href="http://unicode.org/iso15924/iso15924-codes.html">ISO 15924 Code List</link> or
          in the <link href="#extended_script_codes">Extended Script Codes</link> table.  Comparison
          of script codes is performed in a case-insensitive manner, so it does not matter what case
          is used when specifying these codes in an XSL-FO document.</p>
        <section id="standard_script_codes">
          <title>Standard Script Codes</title>
          <p>The following table enumerates the standard ISO 15924 4-letter codes recognized by FOP.</p>
          <table class="ForrestTable tw30">
            <tr>
              <th style="text-align:center">Code</th>
              <th style="text-align:left">Script</th>
            </tr>
            <tr>
              <td style="text-align:center"><code>arab</code></td>
              <td>Arabic</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>beng</code></td>
              <td>Bengali</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>bopo</code></td>
              <td>Bopomofo</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>cyrl</code></td>
              <td>Cyrillic</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>deva</code></td>
              <td>Devanagari</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>ethi</code></td>
              <td>Ethiopic</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>geor</code></td>
              <td>Georgian</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>grek</code></td>
              <td>Greek</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>gujr</code></td>
              <td>Gujarati</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>guru</code></td>
              <td>Gurmukhi</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>hang</code></td>
              <td>Hangul</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>hani</code></td>
              <td>Han</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>hebr</code></td>
              <td>Hebrew</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>hira</code></td>
              <td>Hiragana</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>kana</code></td>
              <td>Katakana</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>knda</code></td>
              <td>Kannada</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>khmr</code></td>
              <td>Khmer</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>laoo</code></td>
              <td>Lao</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>latn</code></td>
              <td>Latin</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>mlym</code></td>
              <td>Malayalam</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>mymr</code></td>
              <td>Burmese</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>mong</code></td>
              <td>Mongolian</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>orya</code></td>
              <td>Oriya</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>sinh</code></td>
              <td>Sinhalese</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>taml</code></td>
              <td>Tamil</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>telu</code></td>
              <td>Telugu</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>thai</code></td>
              <td>Thai</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>tibt</code></td>
              <td>Tibetan</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>zmth</code></td>
              <td>Math</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>zsym</code></td>
              <td>Symbol</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>zyyy</code></td>
              <td>Undetermined</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>zzzz</code></td>
              <td>Uncoded</td>
            </tr>
          </table>
        </section>
        <section id="extended_script_codes">
          <title>Extended Script Codes</title>
          <p>The following table enumerates a number of non-standard extended script codes recognized by FOP.</p>
          <table class="ForrestTable tw70">
            <colgrp>
              <col style="width:10%"/>
              <col style="width:20%"/>
              <col style="width:80%"/>
            </colgrp>
            <tr>
              <th>Code</th>
              <th>Script</th>
              <th>Comments</th>
            </tr>
            <tr>
              <td style="text-align:center"><code>bng2</code></td>
              <td>Bengali</td>
              <td>OpenType Indic Version 2 (May 2008 and following) behavior.</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>dev2</code></td>
              <td>Devanagari</td>
              <td>OpenType Indic Version 2 (May 2008 and following) behavior.</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>gur2</code></td>
              <td>Gurmukhi</td>
              <td>OpenType Indic Version 2 (May 2008 and following) behavior.</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>gjr2</code></td>
              <td>Gujarati</td>
              <td>OpenType Indic Version 2 (May 2008 and following) behavior.</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>knd2</code></td>
              <td>Kannada</td>
              <td>OpenType Indic Version 2 (May 2008 and following) behavior.</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>mlm2</code></td>
              <td>Malayalam</td>
              <td>OpenType Indic Version 2 (May 2008 and following) behavior.</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>ory2</code></td>
              <td>Oriya</td>
              <td>OpenType Indic Version 2 (May 2008 and following) behavior.</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>tml2</code></td>
              <td>Tamil</td>
              <td>OpenType Indic Version 2 (May 2008 and following) behavior.</td>
            </tr>
            <tr>
              <td style="text-align:center"><code>tel2</code></td>
              <td>Telugu</td>
              <td>OpenType Indic Version 2 (May 2008 and following) behavior.</td>
            </tr>
          </table>
          <warning>
            Explicit use of one of the above extended script codes is not portable,
            and should be limited to use with FOP only.
          </warning>
          <note>
            When performing automatic script determination, FOP selects the OpenType Indic
            Version 2 script codes by default. If the author requires Version 1 behavior, then
            an explicit, non-extension script code should be specified in a governing <code>script</code>
            property.
          </note>
        </section>
      </section>
      <section id="language_property">
        <title>Language Property</title>
        <p>Certain fonts that support complex script features can make use of language information in order for
          language specific processing rules to be applied. For example, a font designed for the Arabic script may support
          typographic variations according to whether the written language is Arabic, Farsi (Persian), Sindhi, Urdu, or
          another language written with the Arabic script. In order to apply these language specific features, the author
          may explicitly mark the text with a <link href="http://www.w3.org/TR/2006/REC-xsl11-20061205/#language"><code>language</code></link>
          property.</p>
        <p>When specifying the <code>language</code> property, the value of the property must be either an
          <link href="http://en.wikipedia.org/wiki/List_of_ISO_639-2_codes">ISO639-2 3-letter code</link> or an
          <link href="http://en.wikipedia.org/wiki/List_of_ISO_639-1_codes">ISO639-1 2-letter code</link>.  Comparison of language
          codes is performed in a case-insensitive manner, so it does not matter what case is used when specifying these
          codes in an XSL-FO document.</p>
      </section>
      <section id="writing_mode_property">
        <title>Writing Mode Property</title>
        <p>The <code>writing-mode</code> property is used to determine the axes and direction of the inline
          progression direction, the block progression direction, the column progression direction (in tables
          and flows), the shift direction, region placement, the resolution of writing-mode relative property
          values (such as start, end, before, after), and the default block (paragraph) bidirectionality
          level.
        </p>
        <p>The <code>writing-mode</code> property is inherited, so it can appear on any XSL-FO element type; however,
          it applies (semantically) only to the following element types:
        </p>
        <ul>
          <li><code>fo:page-sequence</code></li>
          <li><code>fo:simple-page-master</code></li>
          <li><code>fo:region-*</code></li>
          <li><code>fo:block-container</code></li>
          <li><code>fo:inline-container</code></li>
          <li><code>fo:table</code></li>
        </ul>
        <p>If it is not specified on one of these element types, but is specified on an ancestor element, then the value specified on that
          ancestor element (the inherited value) is used; otherwise, the initial value <code>lr-tb</code> is used.</p>
        <p>At present, only the following values of the <code>writing-mode</code> property are supported:</p>
        <ul>
          <li><code>lr-tb</code></li>
          <li><code>rl-tb</code></li>
          <li><code>lr</code></li>
          <li><code>rl</code></li>
        </ul>
        <p>Writing modes that employ a vertical inline progression direction are not yet supported.</p>
      </section>
      <!-- [TBD] - NEED TO DOCUMENT
      <section id="number_conversion_properties">
        <title>Number Conversion Properties</title>
      </section>
      -->
      <section id="bidi_override_element">
        <title>Bidi Override Element</title>
        <p>The <link href="http://www.w3.org/TR/2006/REC-xsl11-20061205/#fo_bidi-override"><code>fo:bidi-override</code></link>
          element may be used to override default bidirectional processing behavior,
          including default embedding levels and default character directionality. In the absence of either this element
          or use of explicit <link href="#bidi_controls">Bidi Control Characters</link>, the default behavior prescribed
          by the <link href="http://www.w3.org/TR/2006/REC-xsl11-20061205/#fo_bidi-override">Unicode Bidirectional Algorithm</link>
          applies.
        </p>
      </section>
      <section id="bidi_controls">
        <title>Bidi Control Characters</title>
        <p>In addition to the use of the <link href="#bidi_override_element">Bidi Override Element</link>, an author
          may make use of the following explicit Unicode Bidi Control Characters:</p>
        <ul>
          <li>U+200E - LEFT-TO-RIGHT MARK (LRM)</li>
          <li>U+200F - RIGHT-TO-LEFT MARK (RLM)</li>
          <li>U+202A - LEFT-TO-RIGHT EMBEDDING (LRE)</li>
          <li>U+202B - RIGHT-TO-LEFT EMBEDDING (RLE)</li>
          <li>U+202C - POP DIRECTIONAL FORMATTING (PDF)</li>
          <li>U+202D - LEFT-TO-RIGHT OVERRIDE (LRO)</li>
          <li>U+202E - RIGHT-TO-LEFT OVERRIDE (RLO)</li>
        </ul>
        <p>If an embedding or override is not terminated (using U+202C PDF) prior to the end of a
          <link href="http://www.w3.org/TR/2006/REC-xsl11-20061205/#d0e4879">delimited text range</link>,
          then it is automatically terminated by FOP.
        </p>
      </section>
      <section id="join_controls">
        <title>Join Control Characters</title>
        <p>In order to prevent joining behavior in contexts where joining occurs by default,
          for example, between U+0628 ARABIC LETTER BEH and U+0646 ARABIC LETTER NOON,
          an author may used a U+200C ZERO WIDTH NON-JOINER (ZWNJ).
        </p>
        <p>Conversely, in order to force joining behavior in contexts where joining does not occur by default,
          for example, between U+0628 ARABIC LETTER BEH and U+0020 SPACE, an author may used a U+200D ZERO WIDTH JOINER (ZWJ).
        </p>
        <p>The behavior of ZWNJ and ZWJ is script specific. See
          <link href="http://www.unicode.org/versions/Unicode6.1.0/ch08.pdf">The Unicode Standard, Chapter 8,
          Middle Eastern Scripts</link> for information on the use of these control characters with the Arabic
          script. See
          <link href="http://www.unicode.org/versions/Unicode6.1.0/ch09.pdf">The Unicode Standard, Chapter 9,
          South Asian Scripts - I</link> for information on the use of these control characters with common
          Indic scripts.
        </p>
      </section>
    </section>
    <section id="supported_scripts">
      <title>Supported Scripts</title>
      <p>Support for specific complex scripts is enumerated in the following table. Support
        for those marked as not being supported is expected to be added in future revisions.</p>
      <table>
        <colgrp>
          <col style="width: 15%"/>
          <col style="width: 10%"/>
          <col style="width: 10%"/>
          <col style="width: 65%"/>
        </colgrp>
        <tr>
          <th style="text-align:left">Script</th>
          <th>Support</th>
          <th>Tested</th>
          <th style="text-align:left">Comments</th>
        </tr>
        <tr>
          <td><link href="http://en.wikipedia.org/wiki/Arabic_alphabet">Arabic</link></td>
          <td class="yes">full</td>
          <td class="yes">full</td>
          <td></td>
        </tr>
        <tr>
          <td><link href="http://en.wikipedia.org/wiki/Bengali_alphabet">Bengali</link></td>
          <td class="no">none</td>
          <td class="no">none</td>
          <td></td>
        </tr>
        <tr>
          <td><link href="http://en.wikipedia.org/wiki/Burmese_alphabet">Burmese</link></td>
          <td class="no">none</td>
          <td class="no">none</td>
          <td></td>
        </tr>
        <tr>
          <td><link href="http://en.wikipedia.org/wiki/Devanagari_alphabet">Devanagari</link></td>
          <td class="partial">partial</td>
          <td class="partial">partial</td>
          <td style="text-align:left">join controls (ZWJ, ZWNJ) not yet supported</td>
        </tr>
        <tr>
          <td><link href="http://en.wikipedia.org/wiki/Khmer_alphabet">Khmer</link></td>
          <td class="no">none</td>
          <td class="no">none</td>
          <td></td>
        </tr>
        <tr>
          <td><link href="http://en.wikipedia.org/wiki/Gujarati_alphabet">Gujarati</link></td>
          <td class="partial">partial</td>
          <td class="no">none</td>
          <td style="text-align:left">pre-alpha</td>
        </tr>
        <tr>
          <td><link href="http://en.wikipedia.org/wiki/Gurmukhī_alphabet">Gurmukhi</link></td>
          <td class="partial">partial</td>
          <td class="no">none</td>
          <td style="text-align:left">pre-alpha</td>
        </tr>
        <tr>
          <td><link href="http://en.wikipedia.org/wiki/Hebrew_alphabet">Hebrew</link></td>
          <td class="yes">full</td>
          <td class="partial">partial</td>
          <td></td>
        </tr>
        <tr>
          <td><link href="http://en.wikipedia.org/wiki/Kannada_alphabet">Kannada</link></td>
          <td class="no">none</td>
          <td class="no">none</td>
          <td></td>
        </tr>
        <tr>
          <td><link href="http://en.wikipedia.org/wiki/Lao_alphabet">Lao</link></td>
          <td class="no">none</td>
          <td class="no">none</td>
          <td></td>
        </tr>
        <tr>
          <td><link href="http://en.wikipedia.org/wiki/Malayalam_alphabet">Malayalam</link></td>
          <td class="no">none</td>
          <td class="no">none</td>
          <td></td>
        </tr>
        <tr>
          <td><link href="http://en.wikipedia.org/wiki/Mongolian_script">Mongolian</link></td>
          <td class="no">none</td>
          <td class="no">none</td>
          <td></td>
        </tr>
        <tr>
          <td><link href="http://en.wikipedia.org/wiki/Oriya_script">Oriya</link></td>
          <td class="no">none</td>
          <td class="no">none</td>
          <td></td>
        </tr>
        <tr>
          <td><link href="http://en.wikipedia.org/wiki/Tamil_alphabet">Tamil</link></td>
          <td class="no">none</td>
          <td class="no">none</td>
          <td></td>
        </tr>
        <tr>
          <td><link href="http://en.wikipedia.org/wiki/Telugu_alphabet">Telugu</link></td>
          <td class="no">none</td>
          <td class="no">none</td>
          <td></td>
        </tr>
        <tr>
          <td><link href="http://en.wikipedia.org/wiki/Tibetan_alphabet">Tibetan</link></td>
          <td class="no">none</td>
          <td class="no">none</td>
          <td></td>
        </tr>
        <tr>
          <td><link href="http://en.wikipedia.org/wiki/Thai_alphabet">Thai</link></td>
          <td class="no">none</td>
          <td class="no">none</td>
          <td></td>
        </tr>
      </table>
    </section>
    <section id="supported_fonts">
      <title>Supported Fonts</title>
      <p>Support for specific fonts is enumerated in the following sub-sections. If a given
        font is not listed, then it has not been tested with these complex scripts features.</p>
      <section id="fonts_arabic">
        <title>Arabic Fonts</title>
        <table>
          <colgrp>
            <col style="width: 15%"/>
            <col style="width: 10%"/>
            <col style="width: 10%"/>
            <col style="width: 65%"/>
          </colgrp>
          <tr>
            <th style="text-align:left">Font</th>
            <th style="text-align:left">Version</th>
            <th style="text-align:center">Glyphs</th>
            <th style="text-align:left">Comments</th>
          </tr>
          <tr>
            <td><link href="http://www.microsoft.com/typography/fonts/family.aspx?FID=24">Arial Unicode MS</link></td>
            <td class="yes" style="text-align:left"><link href="http://www.microsoft.com/typography/fonts/font.aspx?FMID=1081">1.01</link></td>
            <td style="text-align:center">50377</td>
            <td>limited GPOS support</td>
          </tr>
          <tr>
            <td><link href="http://scripts.sil.org/cms/scripts/page.php?site_id=nrsi&amp;id=ArabicFonts">Lateef</link></td>
            <td class="yes" style="text-align:left">1.0</td>
            <td style="text-align:center">1147</td>
            <td>language features for Kurdish (KUR), Sindhi (SND), Urdu (URD)</td>
          </tr>
          <tr>
            <td><link href="http://scripts.sil.org/cms/scripts/page.php?site_id=nrsi&amp;id=ArabicFonts">Scheherazade</link></td>
            <td class="yes" style="text-align:left">1.0</td>
            <td style="text-align:center">1197</td>
            <td>language features for Kurdish (KUR), Sindhi (SND), Urdu (URD)</td>
          </tr>
          <tr>
            <td><link href="http://www.microsoft.com/typography/fonts/family.aspx?FID=261">Simplified Arabic</link></td>
            <td class="no" style="text-align:left"><link href="http://www.microsoft.com/typography/fonts/font.aspx?FMID=867">1.01</link></td>
            <td/>
            <td>contains invalid, out of order coverage table entries</td>
          </tr>
          <tr>
            <td><link href="http://www.microsoft.com/typography/fonts/font.aspx?FID=261">Simplified Arabic</link></td>
            <td class="yes" style="text-align:left"><link href="http://www.microsoft.com/typography/fonts/font.aspx?FMID=1645">5.00</link></td>
            <td style="text-align:center">414</td>
            <td>lacks GPOS support</td>
          </tr>
          <tr>
            <td><link href="http://www.microsoft.com/typography/fonts/font.aspx?FID=261">Simplified Arabic</link></td>
            <td class="yes" style="text-align:left">5.92</td>
            <td style="text-align:center">473</td>
            <td>includes GPOS for advanced position adjustment</td>
          </tr>
          <tr>
            <td><link href="http://www.microsoft.com/typography/fonts/family.aspx?FID=264">Traditional Arabic</link></td>
            <td class="yes" style="text-align:left"><link href="http://www.microsoft.com/typography/fonts/family.aspx?FMID=877">1.01</link></td>
            <td style="text-align:center">530</td>
            <td>lacks GPOS support</td>
          </tr>
          <tr>
            <td><link href="http://www.microsoft.com/typography/fonts/font.aspx?FID=264">Traditional Arabic</link></td>
            <td class="yes" style="text-align:left"><link href="http://www.microsoft.com/typography/fonts/font.aspx?FMID=1658">5.00</link></td>
            <td style="text-align:center">530</td>
            <td>lacks GPOS support</td>
          </tr>
          <tr>
            <td><link href="http://www.microsoft.com/typography/fonts/font.aspx?FID=264">Traditional Arabic</link></td>
            <td class="yes" style="text-align:left">5.92</td>
            <td style="text-align:center">589</td>
            <td>includes GPOS for advanced position adjustment</td>
          </tr>
        </table>
      </section>
      <section id="devanagari_fonts">
        <title>Devanagari Fonts</title>
        <table>
          <colgrp>
            <col style="width: 15%"/>
            <col style="width: 10%"/>
            <col style="width: 10%"/>
            <col style="width: 65%"/>
          </colgrp>
          <tr>
            <th style="text-align:left">Font</th>
            <th style="text-align:left">Version</th>
            <th style="text-align:center">Glyphs</th>
            <th style="text-align:left">Comments</th>
          </tr>
          <tr>
            <td><link href="http://www.microsoft.com/typography/fonts/family.aspx?FID=370">Aparajita</link></td>
            <td class="yes" style="text-align:left"><link href="http://www.microsoft.com/typography/fonts/font.aspx?FMID=1700">1.00</link></td>
            <td style="text-align:center">706</td>
            <td/>
          </tr>
          <tr>
            <td><link href="http://www.microsoft.com/typography/fonts/family.aspx?FID=374">Kokila</link></td>
            <td class="yes" style="text-align:left"><link href="http://www.microsoft.com/typography/fonts/font.aspx?FMID=1749">1.00</link></td>
            <td style="text-align:center">706</td>
            <td/>
          </tr>
          <tr>
            <td><link href="http://www.microsoft.com/typography/fonts/family.aspx?FID=243">Mangal</link></td>
            <td class="yes" style="text-align:left"><link href="http://www.microsoft.com/typography/fonts/font.aspx?FMID=1759">5.01</link></td>
            <td style="text-align:center">885</td>
            <td>designed for use in user interfaces</td>
          </tr>
          <tr>
            <td><link href="http://www.microsoft.com/typography/fonts/family.aspx?FID=384">Utsaah</link></td>
            <td class="yes" style="text-align:left"><link href="http://www.microsoft.com/typography/fonts/font.aspx?FMID=1811">1.00</link></td>
            <td style="text-align:center">706</td>
            <td/>
          </tr>
        </table>
      </section>
    </section>
    <section id="limitations">
      <title>Other Limitations</title>
      <p>
        Complex scripts support in Apache FOP is relatively new, so there are certain
        limitations. Please help us identify and close any gaps.
      </p>
      <ul>
        <li>Only the PDF output format fully supports complex scripts features at the present time.</li>
        <li>Shaping context does not extend across an element boundary. This limitation prevents the use of
        <code>fo:character</code>, <code>fo:inline</code> or <code>fo:wrapper</code> in order to colorize
        individual Arabic letters without affecting shaping behavior across the element boundary.</li>
      </ul>
    </section>
    <section id="links">
      <title>Related Links</title>
      <p>
        In addition to the XSL-FO specification, a number of external resources provide
        guidance about authoring documents that employ complex scripts and the features
        described above:
      </p>
      <ul>
        <li><link href="http://www.unicode.org/">The Unicode Standard</link></li>
        <li><link href="http://www.w3.org/TR/2006/REC-xsl11-20061205/#fo_bidi-override">Unicode Bidirectional Algorithm</link></li>
        <li><link href="http://www.microsoft.com/typography/otspec/ttochap1.htm">OpenType Advanced Typographic Extensions</link></li>
        <li><link href="http://scripts.sil.org/cms/scripts/page.php?site_id=nrsi&amp;item_id=CmplxRndExamples">Examples of Complex Rendering</link></li>
      </ul>
    </section>
  </body>
</document>
