Question on draft-ietf-httpbis-cache-latest / RFC7234

[Matthias Pigulla <[e-mail]>]

Dear HTTP Working Group,

this is my first contact with this WG. I've tried my best to read about the necessary procedures and practices. If this the wrong place or way to ask, please excuse me and advise.

My question is on the semantics of the "private" and "public" Cache-Control directives as defined at https://tools.ietf.org/html/draft-ietf-httpbis-cache-06#section-5.2.2.6 and https://tools.ietf.org/html/draft-ietf-httpbis-cache-06#section-5.2.2.5, respectively.

Both state that a (depending on context private, shared or both types of) "cache MAY store the response and reuse it for later requests, even if the response would normally be non-cacheable".

To my understanding, this does not intend to override the requirements from the "Storing Responses in Caches" section (https://tools.ietf.org/html/draft-ietf-httpbis-cache-06#section-3) altogether. Instead, I would assume that it only refers to the condition "has a status code that is defined as heuristically cacheable" in that section (or, as it was stated in RFC7234, "has a status code that is defined as cacheable by default")? 

Would it make sense to amend the list of conditions in that section, appending to the "the response either..." second-level list: "contains a private response directive if the cache is not shared"?

Thank you for clarification.
-mp.