Although this is specifically called out in the ogcapi-record spec, its probably good to do something like this for most outputs.

Basically, the main issue is that the response Content-Type will be fairly generic (i.e. JSON). However, it is "nice" to say what schema/profile that JSON is in.

An example is the ogcapi-records record output. The Content-Type is GeoJSON, but it should say that its profile is ogcapi-record.

1. General - add header (Link) to give the document's profile/schema
2. For OGCAPI-Records, the "links" section should have a rel=profile link defining the schema/profile that this document is in.

cf. opengeospatial/ogcapi-records#478 (comment)