An invalid character was found.
          #3006   Compile-time error
          An invalid character was found.
Additional Information
 The invalid character's decimal code is 'X'.
     or
 The backquote character (`) must either appear in a string or comment, or start a name.
Recovery
The character is ignored.
Explanation
All the printable characters are allowed anywhere in
an OmniMark
program. These include letters, digits, and the punctuation characters:
!@#$%{};:'"`~, <.>/? Spaces are allowed
anywhere. Tabs and carriage returns, where available, are allowed
outside strings. Line-feed and form-feed characters, where available,
are allowed outside strings. All other characters are allowed only
inside comments.