IBM supplies a knowledge base module, CUNMIKBS, that describes all CCSIDs shipped with z/OS Unicode Services. This knowledge base tells z/OS Unicode Services how to convert each type of CCSID. CUNMIKBS is a non-executable load module stored in SYS1.LINKLIB and SYS1.LPALIB. Because CUNMIKBS is an SMP/E managed load module, it is recommended that you modify it by using an SMP/E USERMOD. User-defined CCSIDs can be added to this knowledge base using the assembler macro CUNAIKBG that is supplied in SYS1.MACLIB.

CUNSIUKB is a sample USERMOD, shipped in data set SYS1.SAMPLIB, that can be modified and used to assemble and relink module CUNMIKBS using the CUNAIKBG macro to include user-defined CCSIDs.

In the following example, a new CCSID will be created that will allow z/OS Unicode Services to pass that value on an interface and results in the user-defined conversion.