Consider requirements for specifying the order in which content negotiation is performed

[larsgsvensson]

It would appear that it will necessary to negotiate for profile before language or content-type. Memento specifies that time-based negotiation MUST take place before any other negotiation.

[nicholascar]

Yes I think we need to although will an assertion in this doc be respected by other IETF docs?

Will the PROF-IETF doc, when accepted, necessarily reorder other conneg processes or, put differently, how will clients/servers know which order to believe in the event of a collision of intentions? Does the IETF process sort out those issues before acceptance?

[larsgsvensson]

The IETF document will have to say something on that topic, just as memento does. The question is what we will have to specify.

[nicholascar]

Currently, we don not see strong requirements to specify an order.

[larsgsvensson]

The I-D currently says that servers SHOULD handle Accept-Profile before looking at other negotiation dimensions:

Although servers are free to implement negotiation as they see fit, if the User Agent sends an "Accept-Profile" header, they SHOULD consider representations not conforming to any of the listed profiles as non-interpretable by the client. This means that a representation that conforms to a listed profile, but has a low preference score on other dimensions, SHOULD be considered as more desired than a representation with a higher preference score on other dimensions but that does not conform to any listed profile. If no "Accept-Profile" header preference is given, the profile dimension SHOULD be ignored for negotiation purposes. Nonetheless, in all cases, the server's response SHOULD contain a "Content-Profile" header listing the URIs of all profiles to which it knows the representation conforms.

Shall we add something along those lines to conneg-by-ap, too?