Re: [apps-discuss] "X-" revisited

[Peter Saint-Andre <[e-mail]>]

On 7/6/11 2:53 PM, Dave CROCKER wrote:
> 
> 
> On 7/6/2011 1:05 PM, Peter Saint-Andre wrote:
>>>>   3.  When parameter names need to be very short
>>>
>>> I've no idea how this requirement can justify an x- name.  (A minor
>>> point, but note that x- adds two bytes to the length of the name...)
>>
>> Well, "x-foo" is shorter than "VND.BrandenburgInternetWorking.foo".
> 
> Mumble.  This issue seems like one that is going to take vastly more
> effort than it ought, but that's probably true for the entire topic. 
> (Entire topic:  X- was a good idea to avoid collisions with standards,
> but turns out to be a much worse idea for uses that become standards. 
> So, don't use X-".)
> 
> Anyhow...
> 
> "X-foo" is longer than "foo".
> 
> And I believe the real comparision to VND should be
> "X-BrandenburgInternetWorking.foo"...
> 
> 
>>>> Implementers are easily confused.
>>>
>>> I don't understand how using or not using x- creates or alleviates
>>> confusion in implementers.
>>
>> I don't either, but that was one of the objections.
> 
> OK, but whoever was/is objecting needs to explain their concerns, of
> course.
> 
> 
>>>     2.  Authors of application protocol specifications SHOULD NOT
>>>         mandate that all parameters without the "X-" prefix need
>>>         to be registered with the IANA.
>>>
>>> (#2 seems odd.  I don't really understand why it is needed or what it
>>> does that's significant, given the recommendation of not using x-
>>> parameters ever. Is there a way of stating what is desired
>>> affirmatively?)
>>
>> The point is directed at the kind of thing we find in RFC 5451, which
>> says that x- params MUST NOT be registered and non-x- params MUST be
>> registered. That seems wrongheaded to me.
> 
> OK.  I think this reduces to a new phrasing along the lines of:
> 
>   Authors of application protocol specifications SHOULD provide
> extensible registries for all parameters and SHOULD mandate use of the
> registries, for all values of the parameters, independent of the form of
> the parameter names.

The second SHOULD strikes me as somewhat controversial. :)

The first SHOULD is fine by me, although I'm not sure what an extensible
registry is -- did you mean "both permanent and provisional registries"?

Peter

-- 
Peter Saint-Andre
https://stpeter.im/