(1) A service element (IMS) that is backed up and that can initiate a takeover.
(2) A set of DBCTL subsystem identifiers of equivalent DBCTL subsystems, their associated job names, and the specific APPLIDs of the CICS systems that will use them. RSEs are defined by CICS resource definition macros and are held in the recoverable service table (RST). See also equivalent, recoverable service table.