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

   The /FLAG qualifier lets you specify  whether  the  compiler  informs  you
   about  declining  features,  compatibility  with  PDP-11 BASIC-PLUS-2, and
   compatibility with Compaq BASIC for OpenVMS Alpha.

   The format of the /FLAG qualifier is as follows:

      /[NO]FLAG[=({[NO]BP2COMPATIBILITY},...)]
                  {[NO]DECLINING       }
                  {[NO]AXPCOMPATIBILITY}
                  {ALL                 }
                  {NONE                }

   The /NOFLAG qualifier suppresses  any  warning  messages  about  declining
   features,  compatibility  with PDP-11 BASIC-PLUS-2, and compatibility with
   Compaq BASIC for OpenVMS Alpha.

   /FLAG  =  ALL  is  the  same  as  /FLAG  =  (BP2COMPATIBILITY,  DECLINING,
   AXPCOMPATIBILITY).   /FLAG = NONE is the same as /NOFLAG, and /FLAG is the
   same as /FLAG = ALL.

   The default is /NOFLAG.