RFC 7240, "Prefer Header for HTTP", June 2014Source of RFC: IETF - NON WORKING GROUP
Area Assignment: app
Errata ID: 4439
Reported By: Martin Thomson
Date Reported: 2015-08-09
Verifier Name: Barry Leiba
Date Verified: 2016-02-23
Section 2 says:
preference = token [ BWS "=" BWS word ] *( OWS ";" [ OWS parameter ] ) parameter = token [ BWS "=" BWS word ]
It should say:
preference = preference-parameter *( OWS ";" [ OWS preference-parameter ] ) preference-parameter = parameter / token
Section 1.1 incorrectly states that "word" is defined in RFC 7230. It is not. Therefore, the syntax is completely under-specified.
The "parameter" rule, as defined in RFC 7231, is used in lots of other header field definitions successfully. The only drawback is that "parameter" doesn't permit the use of "OWS" either side of the "=" character.
This change would also require changes to Section 1.1.