wvMap() and vecMap() missing documentation

In this solution and also some old threads here, the wfMap() and vecMap() functions are used.  I see that Virtuoso (IC618 at the moment) knows about these but I can't find them documented anywhere (cdsFinder, docs, even searching on the support web site).  Is that an oversight or are those private?  I do see famMap() documented and have used that many times myself.

https://support.cadence.com/apex/ArticleAttachmentPortal?id=a1Od0000000nX1NEAU&pageName=ArticleContent

Thanks

-Dan