CDMSLIB is the ddname for the load library concatenation for IDMS libraries in a CV's startup JCL. It should not be present in JCL for an IDMS batch job at all.
In an IDMS CV, IDMS for the most part does its own module loading and it uses the ddname CDMSLIB. So the startup JCL of an IDMS CV must have a CDMSLIB which includes the IDMS libraries (CAGJLOAD, CUSTOM.LOADLIB and DBA.LOADLIB) and libraries containing any other modules which will be required to be loaded and executed under the control of the IDMS address space.
CA IDMS, all supported releases.
For the JCL of a batch program accessing an IDMS database, CDMSLIB should not be present. STEPLIB should be used instead. STEPLIB should typically include all of the libraries in the corresponding CV's CDMSLIB and also and libraries containing the user-written batch programs if they are not already included there.