Re: [Iptel] [Editorial Errata Reported] RFC3966 (4376)

[Paul Kyzivat <[e-mail]>]

On 6/8/15 6:11 AM, OKUMURA Shinji wrote:
> Hi Paul,
>
>> On 5/27/15 7:30 AM, OKUMURA Shinji wrote:
>>> Hi,
>>>
>>> phonedigit is used in an extension rule.
>>>
>>>      extension            = ";ext=" 1*phonedigit
>>>
>>> if the original definition is correct, I think a following
>>> description is valid.
>>>
>>> tel:1234;ext=;phone-context=example.com
>>>
>>> May an extension number be an empty string?
>>
>> That would be bad.
>>
>> But your errata fix isn't sufficient for extension because it would
>> allow an extension including only visual-separators. ISTM that to
>> complete the fix the rule for extension also needs to be changed to:
>>
>>    extension            = ";ext=" *phonedigit DIGIT *phonedigit
>
> I see, and IIUC this is reducible as below.
>
>     extension            = ";ext=" *visual-separator DIGIT *phonedigit
>
> The two are equivalent, but from a parser implementor's perspective
> the latter is better (I think).

I agree the two are equivalent. I think one can argue about which is 
easier to understand. But for clarity I do think the same construction 
ought to be used in both the definition of extension and 
global-number-digits. For an errata I think it is preferable to minimize 
the changes to the text, so I think I favor using the form currently 
used in global-number-digits.

(If there was to be another bis, then that would be a good time to 
change it. And then, I think I would define a new rule for this 
construction, that would then be used in both global-number-digits and 
extension.)

	Thanks,
	Paul

> Regards,
> Shinji
>
>>> At the very start what is the reason why visual-separator became an
>>> optional rule?
>>
>> I don't know. It certainly seems to have been a mistake.
>>
>>> according to the document history,
>>>
>>> RFC2806
>>>      phonedigit            = DIGIT / visual-separator
>>>
>>> draft-ietf-iptel-rfc2806bis-01
>>>      phonedigit            =  DIGIT [ visual-separator ]
>>>      phonedigit-hex        =  HEXDIG [ visual-separator ]
>>>
>>> draft-ietf-iptel-rfc2806bis-02
>>>      phonedigit            =  DIGIT / [ visual-separator ]
>>>      phonedigit-hex        =  HEXDIG / "*" / "#" / [ visual-separator ]
>>
>> 	Thanks,
>> 	Paul
>>
>>> Anydody know the intent of this fix?
>>>
>>> Regards,
>>> Shinji
>>>
>>>> This errata should be rejected.
>>>>
>>>> - Jason
>>>>
>>>>
>>>>
>>>> On 5/26/15, 11:47 AM, "RFC Errata System" <[e-mail]>
>>>> wrote:
>>>>
>>>>> The following errata report has been submitted for RFC3966,
>>>>> "The tel URI for Telephone Numbers".
>>>>>
>>>>> --------------------------------------
>>>>> You may review the report below and at:
>>>>> http://www.rfc-editor.org/errata_search.php?rfc=3966&eid=4376
>>>>>
>>>>> --------------------------------------
>>>>> Type: Editorial
>>>>> Reported by: OKUMURA Shinji <[e-mail]>
>>>>>
>>>>> Section: 3
>>>>>
>>>>> Original Text
>>>>> -------------
>>>>> phonedigit           = DIGIT / [ visual-separator ]
>>>>> phonedigit-hex       = HEXDIG / "*" / "#" / [ visual-separator ]
>>>>>
>>>>>
>>>>> Corrected Text
>>>>> --------------
>>>>> phonedigit           = DIGIT / visual-separator;
>>>>> phonedigit-hex       = HEXDIG / "*" / "#" / visual-separator;
>>>>>
>>>>>
>>>>> Notes
>>>>> -----
>>>>> An optional and alternative rule is typically meaningless.
>>>>>
>>>>> Instructions:
>>>>> -------------
>>>>> This erratum is currently posted as "Reported". If necessary, please
>>>>> use "Reply All" to discuss whether it should be verified or
>>>>> rejected. When a decision is reached, the verifying party (IESG)
>>>>> can log in to change the status and edit the report, if necessary.
>>>>>
>>>>> --------------------------------------
>>>>> RFC3966 (draft-ietf-iptel-rfc2806bis-09)
>>>>> --------------------------------------
>>>>> Title               : The tel URI for Telephone Numbers
>>>>> Publication Date    : December 2004
>>>>> Author(s)           : H. Schulzrinne
>>>>> Category            : PROPOSED STANDARD
>>>>> Source              : IP Telephony
>>>>> Area                : Real-time Applications and Infrastructure
>>>>> Stream              : IETF
>>>>> Verifying Party     : IESG
>