VMS Help CC, Command Parameters  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  file-spec,...

      One or more Compaq C source files separated by plus signs or
      commas.  If plus signs are used, the input files are
      concatenated into a single object file.  If commas are used,
      each file is compiled separately to create separate object
      files.  If no input file extension is specified, Compaq C
      assumes the .C default file extension.

  library-file-spec

      A text library containing #include modules referenced in one or
      more of the source files.  A library file specification must be
      concatenated with a file specification with a plus sign and
      qualified using the /LIBRARY qualifier.  If the input file
      extension is not specified, Compaq C assumes the .TLB default
      file extension.