Re: Fwd: i24: Requiring Allow in 405 responses

It's true that for the scope of the base HTTP/1.1 specifications Allow
is completely useless.

However, making it a MAY moves it out of the recommended set of
implementation, forcing every extension who want to use it to negotiate
it's precense to upgrade the requirement to a SHOULD. Quite noticeably
crippling the extension path of HTTP.

If we were talking about OPTIONS *, then I would fully agree with the
others that it's a MAY, but not GET or disallowed methods to a specific
resource. In most cases the server know pretty darn well what methods it
may handle on the resource.

I see no reason why making the requirements for 405 substantially
different than OPTIONS, just confuses implementers.

If the desire is to make Allow a MAY in general then we may just as well
remove it entirely, moving it completely down to extension
specifications, as it makes the feature completely useless from a
specifications point of view as each extension then either MUST upgrade
the requirement to a SHOULD/MUST, or invent their own negotiation
mechanism to announce the extension.

Regards
Henrik




tis 2008-02-12 klockan 23:28 -0800 skrev Mark Nottingham: 
> Thoughts? I have three people who say they prefer MAY, and Robert is  
> starting to convince me...
> 
> 
> Begin forwarded message:
> 
> > Resent-From: ietf-http-wg@w3.org
> > From: Robert Sayre <rsayre@mozilla.com>
> > Date: 12 February 2008 11:11:58 PM
> > To: Mark Nottingham <mnot@mnot.net>
> > Cc: "Roy T. Fielding" <fielding@gbiv.com>, Mark Baker  
> > <distobj@acm.org>, HTTP Working Group <ietf-http-wg@w3.org>, Henrik  
> > Nordström <henrik@henriknordstrom.net>
> > Subject: Re: i24: Requiring Allow in 405 responses
> > Archived-At: <http://www.w3.org/mid/AD1B6FC0-273F-44D6-B925-DE1C3C123101@mozilla.com 
> > >
> >
> >
> >
> > On Feb 13, 2008, at 1:26 AM, Mark Nottingham wrote:
> >
> >>
> >> RFC2119;
> >>> 3. SHOULD This word, or the adjective "RECOMMENDED", mean that  
> >>> there may exist valid reasons in particular circumstances to  
> >>> ignore a particular item, but the full implications must be  
> >>> understood and carefully weighed before choosing a different course.
> >
> >
> > Sure, let's contrast this text with what we have now.
> >
> > "You might help clients out if you send this, no one relies on it,  
> > most people don't bother."
> >
> > Does not sound like something that must be "carefully weighed". I  
> > claim that it doesn't matter a lick, unless you're writing a WebDAV  
> > server or something. By all means, opt in to the MAY in that case.
> >
> > - Rob
> >
> 
> 
> --
> Mark Nottingham     http://www.mnot.net/
>