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                                                   Hypertext Transfer Protocol (HTTP) Problem Types

   Created
   2023-05-02

   Last Updated
   2026-06-26

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   Registry Included Below

     • HTTP Problem Types

HTTP Problem Types

   Registration Procedure(s)

 Specification Required

   Expert(s)

 Mark Nottingham, Sanjay Dalal

   Reference
   [RFC9457]

   Note

 New problem types and changes to existing ones can be requested using
 the [registration request interface] or the [HTTPAPI mailing list].


   Available Formats
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                                                                                            Recommended
                                  Type URI                                        Title     HTTP Status                     Reference
                                                                                               Code
about:blank                                                                   See HTTP      N/A         [RFC9457]
                                                                              Status Code
https://iana.org/assignments/http-problem-types#date                          Date Not      400         [RFC9458, Section 6.5.2]
                                                                              Acceptable
                                                                              Oblivious
                                                                              HTTP key
https://iana.org/assignments/http-problem-types#ohttp-key                     configuration 400         [RFC9458, Section 5.3]
                                                                              not
                                                                              acceptable
                                                                              Unsupported               [RFC-ietf-httpapi-digest-fields-problem-types-06,
https://iana.org/assignments/http-problem-types#digest-unsupported-algorithms Hashing       400         Section 3.1]
                                                                              Algorithms
https://iana.org/assignments/http-problem-types#digest-invalid-values         Invalid       400         [RFC-ietf-httpapi-digest-fields-problem-types-06,
                                                                              Digest Values             Section 3.2]
https://iana.org/assignments/http-problem-types#digest-mismatched-values      Mismatched    400         [RFC-ietf-httpapi-digest-fields-problem-types-06,
                                                                              Digest Values             Section 3.3]

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