Questions have been raised before. I have put in some comments given by people:
* zone-c: * Should be zone contact of closest parent domain with a separate SOA * record? Why duplicate the information?
According to some the zone-c for the closest SOA should be mentioned here. Other suggest that for MX only domains have no zone-c.
Since the MX-only domain is not a zone, there is really no need for a zone-c.
* nserver: * Same as above?
Each domain has a nserver, even an MX only domain. The MX records must be somewhere. This domain has no SOA though.
Same as above -- only zones have name servers, and MX-only domains do not have "name servers" of their own, they live in the parent zone. Thus, this will be duplication of information, and will be harder to maintain consistently whenever anything changes in the name server list of the parent zone.
* sub-dom: * Is it really necessary to list the sub-names in use (this also goes * for the general case, but also for the MX-only case)
If you wish so. Most people do.
Ouch! This is also duplication of information. If you are interested in all domains under a given top-level country domain registered in the RIPE database, you can perform this search by transferring the RIPE database and doing "agrep" on it, no? Or, if people insist that this information should be contained in a single object in the RIPE database, the list of subdomains of a domain could be automatically generated by the RIPE database software (more work for the database software hackers, I know...) - Havard