The method described in the spec to update Resource Set descriptions[1] is supposed to return a HTTP 204 including the _id value of the successfully updated resource set description. 

but the HTTP Status Code Definition for 204 says,

Therefore is it correct to include a body in a 204.

Is it possible to do that? Am I missing a trick here?

[1] https://docs.kantarainitiative.org/uma/draft-oauth-resource-reg.html#rfc.section.2.3.3
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