For integrity reasons, it is sometimes desirable to force the data buffer to be written after a PUT operation. At other times, it is desirable to defer the writing of a buffer when possible to improve performance. At the time the PUT is issued, if the RPL OPTCD specifies direct processing (DIR), and NSP is not specified, forced writing of the buffer occurs. Otherwise, writing is deferred. An ERASE request follows the same buffer writing rules as the PUT request. If LSR and GSR deferred writes are not specified, an ENDREQ macro always forces the current modified data buffer to be written.