Overview of comments
Use the comment filter to insert comments into a pgn file:
      x = _ attacked by k
      comment ("There are "
               #x
               " empty squares in the king's field. They are: "
               x)
    Use hascomment filter to match comments in the PGN file:
hascomment "Good move"
You can instruct the CQL parser to ignore parts of the CQL file using C-style comments:
- Anything on a line following //is ignored
- Anything between the /*and*/sequences is ignored.
    cql()
     check // the  part after 'check' is a comment and is ignored
     Q attacks r
    /* These two lines are ignored
      Second line*/