COBEC9031W Warning - "CPY" extension not specified in COPYEXT directive

The copybook preprocessor, CP, uses the extensions specified by the COPYEXT directive to locate source copybooks. Earlier releases of MCO used different defaults which can be equated to COPYEXT"CPY,cpy,CBL,cbl,". The default setting of COPYEXT on UNIX does not include the uppercase extensions which are required by MCO.
Restriction: This topic applies only when the Enterprise Server feature is enabled.
System Action:
The preprocess/check continues normally but may produce compilation errors if copybooks could not be located.
Resolution:
Ensure that the COPYEXT directive specifies all of the copybook extensions required by your programs. Refer to the MCO documentation for more information about preprocessor changes in this release which may affect the compilation/execution of your CICS programs.
Module:
cicsprep (dfhxc2pp)
Destination:
Source Listing, .TRL file, STDOUT