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

    Provides a means of writing a one-line conditional assembly block.

      .IIF condition [,]argument(s), statement

    condition

    One of the legal condition tests  defined  for  conditional
    assembly blocks.   The  condition  must  be  separated from the
    arguments by a comma, space, or tab.  If the first argument  can
    be  a  blank,  the condition must be separated from the arguments
    with a comma.

    argument(s)

    An expression or symbolic  argument  associated  with  the
    immediate conditional assembly block directive.

    statement

    The statement to be assembled if the condition is satisfied.

    The condition to be tested and the  conditional  assembly  block
    are expressed  completely  within  the line containing the
    directive.  No terminating .ENDC statement is required.