USES             Preserve parameters                                Extension

  USES item [,item]...

    Indicates which registers or single-token data items you want to have
    pushed at the beginning of the enclosing procedure and which ones you
    want popped just before the procedure returns. You must use this
    directive before the first instruction that actually generates code in
    your procedure.

    There is a limit of 8 (eight) items per procedure.

    USES is only available when used with procedures that have a language
    interfacing convention other than NOLANGUAGE.