Re: [dmarc-ietf] PSD flag vs Version bump

[Barry Leiba <[e-mail]>]

> What if MIME-Version changed on every new MIME type?

(I presume you mean "subtype", as we've only defined two new media
types: example (RFC 4735) and font (RFC 8081).)

This is a red herring, as MIME was specifically designed to be
extensible by adding new media types and subtypes, as well as
parameters, charsets, and the like.

We aren't talking about an extension here, but a change to the basic
mechanism of the protocol.  We decided that the change from PSD to
tree walk was sufficiently compatible that it's OK without a version
change.  Removing SPF validation is a less compatible change to the
protocol, and it makes it a different discussion.

Best to avoid analogies: most of them fail and are only distracting.

Barry