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

    Evaluates the  specified  floating-point  constants  and  stores
    the results  in the object module.  .H_FLOATING generates 128-bit
    data (1 bit of sign, 15 bits of exponent, and 112 bits of
    fraction).

      .H_FLOATING literal-list

    literal-list

    A list of floating-point constants.  The constants cannot contain
    any unary or binary operators except unary plus or unary minus.

    H_floating-point numbers are always rounded.  They are  not
    affected by the .ENABLE TRUNCATION directive.

    The floating-point constants in the literal list must not be
    preceded by the floating-point operator (^F).