[91] comment declaration =
 2         mdo,                                           [ <! ]
           ( comment,                             [ [92] 391: 7]
 4           ( s |                                [  [5] 297:23]
               comment )* )?,                     [ [92] 391: 7]
 6         mdc                                            [  > ]
    
   [92] comment =
 8         com,                                           [ -- ]
           SGML character*,                       [ [50] 345: 1]
10         com                                            [ -- ]
    
   No markup is recognized in a comment [ [92] 391:7], other than the
12 com delimiter that terminates it.