Comments on httpbis-client-hints-01

Hi,

A few comments on draft-ietf-httpbis-client-hints-01:

1. It seems to imply that Vary only includes the hints that were
present in the request ("emit a Vary . . . to indicate which hints
were used"). But, for example, if the request had *no* DPR field, yet
the response *would* be influenced by a DPR field, shouldn't the
response still include "Vary: DPR"?Otherwise a cache cannot know that
a subsequent request with DPR must be written through to the origin
server.

2. The Accept-CH field seems underspecified. Is it per-resource? (and
if so, doesn't it duplicate Vary?) Or is it per-origin? Or does it
just apply to resources linked from the response?

3. Are requirements like "If DPR occurs in a message more than once"
(ditto for the other fields) useful? Duplicating these fields is
already invalid per RFC 7230.


-- 
Vasiliy

Received on Friday, 3 June 2016 09:49:04 UTC