I am looking for a way that you, or anyone else, could indicate a domain should not be considered "in service" although the name is registered and has an A record pointing to an active server so when I check that name it doesn't require a human to interpret the results.
You might be able to use lack of an SOA record as a hint. In my experience, parked domains often do not have SOA records because the parking companies are lazy. It is a lot easier to put all the parked domains in a parent zone file, or even use a wildcard, rather than have a zone file for each parked name. Duane W.
