A URI reference [RFC3986] that identifies the problem type.
This specification encourages that, when dereferenced,
it provide human-readable documentation for the
problem type (e.g., using HTML [W3C.REC-html5-20141028]).
When this member is not present, its value is assumed to be "about:blank".

A short, human-readable summary of the problem type.
It SHOULD NOT change from occurrence to occurrence of the problem,
except for purposes of localization
(e.g., using proactive content negotiation; see[RFC7231], Section 3.4).

The HTTP status code ([RFC7231], Section 6)
generated by the origin server for this occurrence of the problem.

A human-readable explanation specific to this occurrence of the problem.

A URI reference that identifies the specific occurrence of the problem.
It may or may not yield further information if dereferenced.