Reason Phrase provides a way for the sender to encode additional diagnostic information about an error condition, where appropriate.
Reason Phrase {
Reason Phrase Length (vi64),
Reason Phrase Value (..)
}
-
Reason Phrase Length: A variable-length integer specifying the length of the reason phrase in bytes. The reason phrase length has a maximum value of 1024 bytes. If an endpoint receives a length exceeding the maximum, it MUST close the session with a
PROTOCOL_VIOLATION -
Reason Phrase Value: Additional diagnostic information about an error condition. The reason phrase value is encoded as UTF-8 string and does not carry information, such as language tags, that would aid comprehension by any entity other than the one that created the text.