There are some DFSMS modules that CICS® loads from the MVS™ linklist. This requirement is either dependent on the function you are using (such as backup-while-open (BWO) support), or on the release of DFSMS. The modules are:
For files that are accessed in RLS mode, CICS does not require IGWABWO or IGWAMCS2.
DFHFC0116 APPLID THE LOAD OF CALLABLE
SERVICE IGWARLS HAS FAILED WITH RETURN CODE
X'EEEE'.
CICS initialization fails if CICS cannot load this callable services module.