Re: [Gen-art] Gen-ART LC review of draft-hanes-dispatch-fax-capability-06.txt

[Brian E Carpenter <[e-mail]>]

On 05/12/2012 11:01, Kevin Fleming wrote:
> The language in RFC 3840 doesn't appear to contemplate the situation you've
> proposed. In its world, registrars can either support prefs (and will
> accept "Require: pref") or they don't, and they don't have knowledge of
> which feature tags are registered with IANA and which are not. Of course,
> they *coud* attempt to validate the tags expressed by the UA, but I don't
> see an explicit way for the registrar to indicate that the UA included
> disallowed tags in its request.

Understood, but in that case I don't see what good the confirmation
of the tag from the registrar to the UA achieves - the UA is not going
to be able to do anything with it (except maybe log whether it was
received).

    Brian