The $XABRDT_STORE macro moves user-specified values into fields
    of the specified XABRDT. The expanded $XABRDT_STORE code executes
    at run time on a previously initialized (allocated) XABRDT, in
    contrast to the $XABRDT macro, which initializes the XABRDT at
    assembly time. The $XABRDT_STORE macro must reside in a code
    program section.

    Format

      $XABRDT_STORE  XAB=xabrdt-address,

                     RDT=#revision-date-time,

                     RVN=#revision-number,

                     NXT=next-xab-address