mixing different direction labels within same domain

JFC Morfin jefsey at jefsey.com
Mon Aug 8 14:57:08 CEST 2011

Dear Abdulrahman, dear Slim,

we try to consolidate all the post-IDNA2008 points that are now to be 
addressed at Internet technology level (including those with an 
impact on the protocols but belonging to the architectural level that 
we plan to consolidate further on). This mostly concerns inputs from 
IUCG, IUTF, ALFA, ITU, John Klensin, Andrew Sullivan, Paul Hoffman, 
Vint Cerf, etc. The target is to help them all to consistently work 
in being aware of all the issues and in using the same terms with the 
same meaning.

The current version of this compilation is at 

Once we have compiled all the potocol level issues we will propose 
all the concerned parties to consolidate them into a common Draft to 
everyone's benefit and for us to complete the design of an ML-DNS 
prototype implementation, i.e. a multi-layer, multi-prupose 
(intertechnology), multi-orthotypography IDNA2008 
conformant  front-end of the IDNA2008 stabilised Internet DNS.

Among the points we noted there is the Bidi issue 
http://iucg.org/wiki/Bidi_discussion that you raised on 2/14/2010. 
Harald's response is at the IDNA2008 level (on the Internet side). 
The question now is to know how to address it at the use level: I 
would be interested in a description of the problem which could 
permit a solution at protocol, use or architural level.

I thank you if you can help us.

At 22:55 07/08/2011, Harald Alvestrand wrote:
>On 06/21/11 07:55, Abdulrahman I. ALGhadir wrote:
>>Dear all,
>>I am just wondering whenever it is permitted or not to have this case:
>><r2l chars><num1>.<num2>.<etc ..>
>This particular case has all labels legal, but the overall display 
>name will display very oddly (as noted). The oddity is caused by our 
>inability to mandate whole-domain tests, as described in the RFC.
>It is logical for the administrator of <etc ..> to forbid 
>registration of leading-numeric labels if it anticipates R2L labels 
>at the next level down, and it is logical for application writers to 
>simply reject such names because they are going to confuse the users 
>(much in the spirit of Firefox' refusal to do mixed-script names), 
>but the RFC does not require them to do so.
>>As you know in case r2l labels the display will be like this
>><etc..>.<num1>.<num2><r2l chars>
>I think the display will depend on the direction of <etc> and 
>whether it is in an RTL context or an LTR context, but I'm still not 
>confident of my ability to execute the BIDI algorithm in my head.
>>As you see both of them have different display order which 
>>isn't  the same as network order.
>>And I know it is mentioned in the RFC
>>    Several stronger statements were considered and rejected, because
>>    they seem to be impossible to fulfill within the constraints of the
>>    Unicode bidirectional algorithm.
>>And one of the statement is
>>   o  The sequence of labels should be consistent with network order.
>>       This proved impossible -- a domain name consisting of the labels
>>       in network order) L1.R2.R3.L4 will be displayed as L1.R3.R2.L4 in
>>       an LTR context.  (In an RTL context, it will be displayed as
>>       L4.R3.R2.L1)
>>And I have tried two implemented tools (well I don't know if they 
>>follow the RFC fully or not).
>>Idna-update mailing list
>><mailto:Idna-update at alvestrand.no>Idna-update at alvestrand.no
>Idna-update mailing list
>Idna-update at alvestrand.no
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