Program CMNVSRVC executes exactly the same underlying ChangeMan ZMF Services as its public-facing equivalent, the XML Services (i.e. programs SERXMLxC). Several of the ISPF skeletons (skels) shipped with the product execute required services using CMNVSRVC rather than SERXMLBC or any of its SERXMLxC counterparts.

The XML Services and their associated tags are fully documented in various product manuals and KB articles. However, the CMNVSRVC keywords used in the distributed skels are not documented. 

For various reasons, customers may need to verify or customize the shipped skels to investigate issues and/or include additional parameters/keywords that are required in their environment. 

Full article: https://portal.microfocus.com/s/article/KM000013873