Julian's feedback

[mnot]

2.1. About Intermediaries

An immutable response has the same semantic meaning when received by
proxy clients as it does when received by User-Agent based clients.
Therefore proxies SHOULD skip conditionally revalidating fresh
responses containing the immutable extension unless there is a signal
from the client that a validation is necessary (e.g. a no-cache
Cache-Control request directive).

Maybe point to Section 5.2.1.4 of RFC 7234 here...

A proxy that uses immutable to bypass a conditional revalidation may
choose whether to reply with a 304 or 200 to its requesting client
based on the request headers the proxy received.

s/may/MAY/ or s/may/can/

2.2. Example

Cache-Control: max-age=31536000, immutable

Maybe add a full example, including a request/response pair for the case when "immutable" is not present?

4. IANA Considerations

[RFC7234] sections 7.1 and 7.1.2 require registration of the

s/[RFC7234] sections 7.1 and 7.1.2/Section 7.1 of .../

[mcmanus]

Maybe add a full example, including a request/response pair for the case when "immutable" is not present?

I actually toyed with this originally and decided the current arrangement was better. Drawing the absence of a request (or the case when nothing is different from the 723x state) didn't really clarify the normative text. It turned out better to just focus on the syntax of immutable in a response imo.

[mcmanus]

remainder addressed in -03. thanks