VMS Help MACRO, VAX MACRO Assembler, Directives, .DEFAULT  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Determines the default  displacement  length  for  the  relative
    and relative deferred addressing modes.

      .DEFAULT DISPLACEMENT, keyword

    keyword

    One of three keywords - BYTE, WORD, or LONG - indicating the
    default displacement length.

    This has no effect on the default displacement for  displacement
    and displacement deferred addressing modes.  If there is no
    .DEFAULT in a source module, the default displacement length for the
    relative  and relative deferred addressing modes is a longword.