[HECnet] Wanted: details on "system specific" NICE messages

I'm thinking it would be nice (in the tools with PyDECnet) to be able to do not just standard NICE requests like any other NCP, but also system-specific ones. I can find out what the RSTS ones look like, but I don't know about other systems. I'm pretty sure that both VMS and RSX have system-specific requests, SHOW and/or SET, for things like network objects or logical links and perhaps other stuff. Is there documentation that describes these? Does anyone have information handy? A few days ago VMS listings (from fiche) appeared in Bitsavers, and I suppose I can try to read NCP listings that are in there. Chances are they are in BLISS which I don't know at all... paul