Hi, https://www.rfc-editor.org/rfc/inline-errata/rfc2183.html says what to do if the disposition type is unrecognised, but not what to do if the Content-Disposition field does not parse. For example, Content-Disposition: =?utf-8?Q?inline?= is being seen on real-life emails due to a bug. Given RFC 2183's grammar, disposition := "Content-Disposition" ":" disposition-type *(";" disposition-parm) disposition-type := "inline" / "attachment" / extension-token ; values are not case-sensitive coupled with RFC 2045, extension-token := ietf-token / x-token ietf-token := <An extension token defined by a standards-track RFC and registered with IANA.> x-token := <The two characters "X-" or "x-" followed, with no intervening white space, by any token> that field does not parse so RFC 2183's Unrecognized disposition types should be treated as `attachment'. 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? - Is there an overarching clause in another email RFC which says something like an field which does not parse is considered to not exist? -- Cheers, Ralph.
