the current draft talks about a profile media type parameter, and recommends using it to link to a JSON schema. the existing https://tools.ietf.org/html/rfc6906 about profiles (that also talks about "profile" media type parameters) is not referenced, but at least there is some overlap. please consider that the idea of profiles (as specified in RFC 6906) is not to interlink instances and schemas. instead, the idea is that a profile identifies a set of rules applied to an instance which can be processed with or without knowing the profile-specific processing rules.