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

     /MMS_DEPENDENCIES[=(option[,option)]]
     /NOMMS_DEPENDENCIES (D)

  Directs the compiler to produce a dependency file.  The format of
  the dependency file is identical to that on OSF:

     object_file_name :<tab><source file name>
     object_file_name :<tab><full path to first include file>
     object_file_name :<tab><full path to second include file>

  You can specify none, one, or both of the following qualifier
  options:

   FILE[=filespec]        Specifies where to save the dependency
                          file.  The default file extension for a
                          dependency file is .mms.  Other than using
                          a different default extension, this
                          qualifier uses the same procedure that
                          /OBJECT and /LIST use for determining the
                          name of the output file.

   SYSTEM_INCLUDE_FILES   Specifies whether or not to include
                          dependency information about system include
                          files (that is, those included with
                          #include <filename>).  The default is to
                          include dependency information about system
                          include files.

                          Note that the /OBJECT qualifier has no
                          impact on the dependency file.