Clarification on 'GETINFO exit-policy/*'s valid 'non-transient internal errors'

Hi network team. I was just about to tweak Stem to treat 552 GETINFO response codes as "I'm not configured to be a relay" per...

https://trac.torproject.org/projects/tor/ticket/25853 https://trac.torproject.org/projects/tor/ticket/25852 https://gitweb.torproject.org/torspec.git/commit/?id=c5453a0

However, the spec addition says "Will send 552 error if the server is not running as nion router or if there's non-transient internal error." So I'm unsure what the response code actually indicates. If we are a relay that what are the scenarios where tor validly returns a 552?

For now in stem gonna pretend that part doesn't exist and 552s indicate 'not a relay'. :)