Re: #147: header-specific canonicalisation

On Wed, 3 Mar 2010, Mark Nottingham wrote:

> This has been discussed on-list and in meetings sporadically, but I don't think we've ever focused on it exclusively.
>
> <http://trac.tools.ietf.org/wg/httpbis/trac/ticket/147>
>
>
> Current text at <http://tools.ietf.org/html/draft-ietf-httpbis-p6-cache-08#section-2.6>:
>
>>    The selecting request-headers from two requests are defined to match
>>    if and only if the selecting request-headers in the first request can
>>    be transformed to the selecting request-headers in the second request
>>    by adding or removing linear white space [[anchor8: [
>> ref
>> ]]] at places
>>    where this is allowed by the corresponding ABNF, and/or combining
>>    multiple message-header fields with the same field name following the
>>    rules about header fields in
>> Section 3.2 of [Part1].
>
> Proposed replacement:
>
>  The selecting request-headers from two requests are defined to match
>  if and only if those in the first request can be transformed to those in the
>  second request by applying any of the following:
>    - adding or removing whitespace, where allowed in the headers' ABNF
>    - combining multiple message-header fields with the same field name (see
>       Section 3.2 of [Part1])
>    - canonicalising both headers' values in a way that is known to have identical
>       semantics, according to the headers' specification (e.g., re-ordering field values
>      when order is not significant; case-normalisation, where values are defined to be
>      case-insensitive)

Friendly amendment: s/Canonicalising/Normalizing/

-- 
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         ~~Yves