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

    Aligns the location counter to the boundary specified  by  either
    an integer or a keyword.

      .ALIGN integer[,expression]
      .ALIGN keyword[,expression]

    integer

    An integer in the range of 0 through  9.   The  location  counter
    is aligned  at  an address that is the value of 2 raised to the
    power of the integer.

    keyword

    One of five  keywords  that  specify  the  alignment  boundary.
    The location  counter  is aligned to an address that is the next
    multiple of the values listed below.

      Keyword     Size (in Bytes)
       BYTE          2^0 = 1
       WORD          2^1 = 2
       LONG          2^2 = 4
       QUAD          2^3 = 8
       PAGE          2^9 = 512

    expression

    Specifies the fill value to be stored in each byte.   The
    expression must  not  contain  any  undefined  symbols  and  must
    be an absolute expression.