  The CCmgidCA utility simply sets the group ID of all files it is given to the
  same as that of CCmgidCA and CCmbbsCA. If you are running a BBS system using a
  setgid CCmbbsCA client, then this utility allows users who are not members of
  the "bbs" group to make their files available on the BBS.

  A typical sequence of commands would be:

   touch newfile.cm
mgid newfile.cm
chmod 660 newfile.cm

  This would create the file newfile.cm and make it readable and writeable by
  its owner and by users of the BBS.

