[ replies directed to ietf-822 which is more germane to this topic ] On Sat, 26 Sep 2020, Ralph Corderoy wrote:
Content-Disposition: =?utf-8?Q?inline?=
Yuck. But I can believe it.
does not apply as we do not have a disposition type, recognised or not. - Am I missing something in RFC 2183 which describes what to do in that case?
No, IETF standards generally tell you how to interoperate with other people who implement the standards, on the perhaps optimistic assumption that they will read the specs and follow them, not how to work around breakage.
- Is there an overarching clause in another email RFC which says something like an field which does not parse is considered to not exist?
There are a few cases where we've said things like that, e.g., an invalid DKIM signature is equivalent to no DKIM signature, but in general trying to guess what someone meant when they do something invalid is hopeless.
Or to look at it another way, if a sender doesn't care enough to say correctly what they would like me to do with their mail, I don't care enough to try to guess what they might have meant.
Regards, John Levine, johnl@xxxxxxxxx, Primary Perpetrator of "The Internet for Dummies", Please consider the environment before reading this e-mail. https://jl.ly
