Re: [dmarc-ietf] Definition of "value" in RFC8601

[Damian Lukowski <[e-mail]>]

>> This seems equivalent to
>>> authserv-id = sub-domain *("." sub-domain)
>>>    ; Where sub-domain is imported from 6531 for
>>>    ; any mail
> No, it's 6531 for EAI messages, and 5321 for ASCII messages.

If they are not equivalent, there must be a counterexample in which a
parser with

> authserv-id = sub-domain *("." sub-domain)
>    ; Where sub-domain is imported from 6531 for
>    ; any mail
and another parser with

> authserv-id = sub-domain *("." sub-domain)
>    ; Where sub-domain is imported from 5321 for ASCII mail
>    ; and 6531 for EAI mail.

, given identical input, disagree on the validity of the A-R header of
that input. Can you please show an example?

> EAI and ASCII mail are separate mail streams. The component that is
> parsing the A-R header had better know ahead of time whether your
> system is treating them separately.

Can you elaborate on this paragraph? Know what ahead of time? It sounds
like you agree, that the validity of an A-R header does depend on
external factors, not solely on the A-R content.