VMS Help NCS Command, Command Qualifiers, /FORMAT  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  /FORMAT=option

   When you specify a MACRO output file with the /MACRO qualifier,  use
   this qualifier to specify the appropriate Macro-32 file format.  You
   may select one of two format options,  either  NCS  (the default) or
   256. If you select NCS, NCS formats the  collating  sequence  and/or
   string conversion tables for use by the NCS routines.  If you select
   256, NCS formats the the collating sequence and/or string conversion
   tables as 256-byte tables that can be used by the  run-time  library
   routine LIB$MOVTC.