RFC 2387, "The MIME Multipart/Related Content-type", August 1998Source of RFC: mhtml (app)
Errata ID: 5048
Status: Held for Document Update
Reported By: Adrian Kennard
Date Reported: 2017-06-22
Held for Document Update by: Barry Leiba
Date Held: 2019-04-30
Section 3.4 says:
related-param := [ ";" "start" "=" cid ] [ ";" "start-info" "=" ( cid-list / value ) ] [ ";" "type" "=" type "/" subtype ] ; order independent
It should say:
Unsure of best way to express this, but this syntax does not seem to allow for the values to be in quotes. e.g. type="text/html" rather than type=text/html
Basically, the examples all have quotes around the values, e.g. type="Application/X-FixedRecord" rather than type=Application/X-FixedRecord
It appears that Yahoo email cannot accept type=text/html as per "syntax" in 3.4, but will accept type="text/html" which is consistent with the examples
The examples in the RFC currently do not comply with the RFC.
----- Verifier Notes -----
I think the last sentence in the submitter's notes is the correct one: it's the examples that are wrong, not the ABNF -- the values are not intended to be in quotes. In any case, this needs to be dealt with in a revision of the document, so we're sure we get it right and consider what multiple implementations are doing.