Re: Zaheduzzaman Sarker's No Objection on draft-ietf-httpbis-targeted-cache-control-03: (with COMMENT)

> On 18 Jan 2022, at 7:21 pm, Zaheduzzaman Sarker via Datatracker <> wrote:
> I have only one observation - CND-Cache-Control is a targeted for CDN caches,
> however, my understanding is this can end up in the clients. There is no
> description or reference to description about what a client supposed to handle
> this (obvious is to ignore). It would be great if we can write something about
> it or refer to the client behavior description elsewhere. If my understanding
> is wrong that this header field will never reach any client then I would say it
> requires some wording in the specification to clearly state that.

This is the case for all HTTP fields -- implementations that aren't consuming a field ignores it. That allows extensibility.

Furthermore, the spec already says: "Targeted fields that are not on a cache's target list MUST NOT change that cache's behaviour, and MUST be passed through."

Note that a cache is a component that's separate and independent from clients or servers -- i.e., a client or server can have a cache.


Mark Nottingham

Received on Thursday, 20 January 2022 03:47:34 UTC