CA DADS Plus for CICS fix RO99057 makes references to Z/OS 2.3. The fix description is
CTS 5.4 ADDITIONAL CA DADS PLUS SUPPORT
Is CA DADS Plus CICS fix RO99057 required for Z/OS 2.3?
Fix RO99057 is not a Z/OS 2.3 fix. The comments were added by mistake and can be ignored. This fix is only required if you upgrade to CTS 5.4.
In CICS 5.4 a control block was changed that required an update to the CA DADS Plus for CICS RDO entries for CICS 5.4 sample library member RDO71.