Which document is RFC1036, that you cite? Sorry, but I'm lousy remembering
numbers. (...I stopped memorizing them with RFC823...?)
If it is a publication of some other group's 'standard' then it is
possible that it can be cited by another Internet standards-track doc. If
it is a random Internet doc which is not on standards track, then I
think you are right about the difficulties in citing it.
However, Internet standards rules are not meant to prevent 'the right thing'
from being done, so I suggest that you formulate design decisions based
upon whatever you and the group think is right. If you cross into
unfirm territory, spin off a question to the IETF management, through
Greg as WG chair, and ask how to resolve an apparent confusion/conflict.
Dave