In addition to transferring these values for sending response information, the PLU application program can analyze these fields to determine what to do next. It can:

• Begin sequence number resynchronization, using the SESSIONC macroinstruction.
• Await a Request Recovery (RQR) request from the LU (which would cause scheduling of the program's SCIP exit routine) and then begin sequence number resynchronization. In this case, the LU must be capable of deciding whether to shut down or to request recovery.
• If in the process of receiving a chain of requests, set a flag to purge the buffer that contains requests in this chain that have been previously received. It can set a flag to indicate to itself that the rest of the requests in this chain are to be disregarded. When the last request arrives, the program can turn off this flag.