(1) In CICS Transaction Server 3.3 (and earlier) and CICS/VSE, a user-replaceable CICS program (DFHRTY) used to modify the conditions under which a transaction is restarted by CICS after dynamic transaction backout.
(2) In CICS Transaction Server 4.1 (and later), a user-replaceable program (DFHREST) that enables you to participate in the decision as to whether a transaction should be restarted or not.