REM [ ... ]

   Synopsis:
      Marks the rest of the line as a comment

   Notes:
      Everything after the REM keyword is ignored. The '!' character can be used
         interchangeably with REM.

   Examples:
      REM This whole line is a comment
      ! This whole line is a comment

      PRINT "Hello!" : REM  Only the word 'Hello' is displayed
      PRINT "Hello!"   !    Only the word 'Hello' is displayed
