Appendix A. Changes from RFCs 2616 and 2617

The framework for HTTP Authentication is now defined by this document, rather than RFC 2617.

The "realm" parameter is no longer always required on challenges; consequently, the ABNF allows challenges without any auth parameters. (Section 2)

The "token68" alternative to auth-param lists has been added for consistency with legacy authentication schemes such as "Basic". (Section 2)

This specification introduces the Authentication Scheme Registry, along with considerations for new authentication schemes. (Section 5.1)

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