> In this document, it will specifically cover [proactive negotiation](https://datatracker.ietf.org/doc/html/rfc7231#section-3.4.1) using the [Accept](https://datatracker.ietf.org/doc/html/rfc7231#section-5.3.2) header. RFC 7231 is obsoleted by RFC 9110. The current guidance regarding Content Negotiation and the Accept header is: - https://datatracker.ietf.org/doc/html/rfc9110#name-proactive-negotiation - https://datatracker.ietf.org/doc/html/rfc9110#field.accept