/sys$common/syshlp/helplib.hlb CC, Language topics, Preprocessor, #define  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  The #define preprocessor directive has the form:

       #define identifier token-string

  The preprocessor substitutes the token string everywhere in the
  program that it finds the identifier except within comments,
  character constants, or string constants.

  Macro replacements are defined in a #define directive of the
  following form:

       #define name([parm1[,parm2,...]]) token-string

  Within the program, all macro references that have the following
  form are replaced by the token string.  The arguments in the macro
  reference replace the corresponding parameters in the token string.

       name([arg1[,arg2,...]])