# GNU sed accepts end-of-line comments with no ; before.
### foo
#foo
#
/foo/ {                                ;# c1;c1
    # foo;bar
    #;
    p                                  ;#p1
    p                                  ;# p2
    p                                  ;### p3
    p                                  ;# p4;p4
    p                                  ;# p5
    s/a/b/                             ;#s1
    s/a/b/                             ;# s2
    s/a/b/gp                           ;#s3
    s/a/b/gp                           ;# s4
    :foo                               ;#l1
    :foo                               ;# l2
    b foo                              ;#b1
    b foo                              ;# b2
    b                                  ;#b3
    b                                  ;# b4
}                                      ;# c2
#
