IBM SC33-1683-02 - Manual (Page 157)

Front End Programming Interface exits XSZARQ and XSZBRQ
Exits XSZARQ and XSZBRQ are invoked from the CICS/ESA Front End
Programming Interface (FEPI), if FEPI is installed. For details of these exits, see the
CICS Front End Programming Interface User’s Guide.
Front End Programming Interface exits
Chapter 1. Global user exit programs 125