Problem description
Please see feedback from @hdamker in PR #15, in particular around 406 and 5XX error codes

Expected action

• Decide if 406 and 5XX response codes should be in OAS definition
• Decide if either (or both) endpoints should be mandatory, in which case 501 should not be an option.

Additional context
406 and 5XX response codes are now optional for the OAS definition

501 should be included if the endpoint is optional.

My preference is that both endpoints should be mandatory (it is no more difficult to implement both than just one, and the data is not particularly sensitive from a privacy point of view). Hence I think 406 and all 5XX codes should be removed for the release candidate.