By using macros, you can use a single source statement to insert
    a sequence of source statements into a program.

    A macro definition contains the source statements of the macro.
    The macro definition may have formal arguments. You can use these
    formal arguments throughout the sequence of source statements
    within the definition. When the macro is called, the formal
    arguments are replaced by the actual arguments within the macro
    call.

    The macro call is a single source statement consisting of the
    macro name, optionally followed by arguments. When the macro
    is called, the assembler replaces the line containing the macro
    call with the source statements in the macro definition. The
    assembler replaces any occurrences of formal arguments in the
    macro definition with the actual arguments specified in the macro
    call. This process is called the macro expansion.

    By default, macro expansions are not printed in the assembly
    listing. To print the macro expansions, you must specify the
    /SHOW=EXPANSIONS qualifier and argument in the command line. Note
    that the examples of macro expansions used in this chapter are
    listed as they would appear using the /SHOW=EXPANSIONS qualifier
    and argument.

    Use .SHOW with a symbolic argument of EXPANSIONS in the source
    text of a program to specify the listing of expansions.