CACHING-6 failure message: what is an "invalid" value?

Hi,

The CACHING test defines CACHING-6 as:
  [[ If any cache related header contains an invalid value, warn ]]
  http://www.w3.org/TR/mobileOK-basic10-tests/#CACHING

What exactly constitutes an "invalid" value? For instance, looking at 
the definition of the Cache-Control header field in the HTTP RFC, I see 
that cache-response-directive may be a cache-extension:
  http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.9

Are such cache-extension directives considered to be invalid values? 
I.e. are we trying to alert authors on the fact that unusual 
cache-control directives are unlikely to be understood, or is this 
warning only motivated by real invalid values such as: "Cache-Control: =" ?

I'd go for the latter proposal, but the mobileOK Checker library 
currently does the former.
Minor bug or feature?

Francois.

Received on Thursday, 3 September 2009 16:00:05 UTC