Comments document the actions or elements  of  a  program.   The
  text  of  a  comment  can  contain  any ASCII character except a
  nonprinting control character, such as an ESCAPE character.  You
  can  place  comments  anywhere in a program that white space can
  appear.

  You signify a comment with braces  or  with  a  parenthesis  and
  asterisk pair, as follows:

  Example:

     { This is a comment }
     (* This is also a comment *)

  VSI Pascal allows you  to  mix  the  two  symbol  pairs  in  one
  comment, as follows:

     { The delimiters of this comment do not match. *)
     (* VSI Pascal allows you to mix delimiters in this way. }

  VSI Pascal does not allow you to nest comments.   The  following
  example  causes a compile-time error because the comment ends at
  the first closing delimiter (}).

  Example
     The following is illegal:
     (* Comments can not be nested { in VSI Pascal } within
         a program *)