BIDI rules

Harald Tveit Alvestrand harald at alvestrand.no
Thu Sep 4 17:21:39 CEST 2008


Alireza Saleh skrev:
> I did some tests on domain visualization when we have RTL characters in the
> label. Some issues arise when you mix the scripts within a domain.
>
>
> As the group decided to eliminate the inter-label checking within the
> protocol in Dublin, and inter-label checks are quite essential, it is
> necessary that these be done SOMEWHERE. Consider, for example, the
> following where LTR and RTL cannot be distinguished:
>
>
> 1) http://3.ا.com = http://3.<ALEF>.com
> 2) http://ا.3.com = http://<ALEF>.3.com
>   
Alireza,

I am confused by this example - on my screen, the left hand side of 
example 2) contains two non-ASCII charcters and no digit 3, so the two 
are quite visually distinct to me. Could you explain a bit more?

Since I don't understand your example, it's possible that I'm entirely 
off track in my responses below - so please consider these only 
preliminary musings.
>
> After the label checks in IDNA2008 there are many unfixed and known issues
> that remain to be done somewhere else, such as at the application level or
> at the registry. For example the Registry should also apply more
> restrictive rules during the registration to make their TLD safe but this
> will not assure safety beyond the second level. Here applications will be
> expected to take on the safety problems.
>
>
> After the introduction of IDNA, most application developers have been
> thinking about secure ways to make sure users will see the correct
> domain  Some applications may also change direction from LTR to RTL based
> on what they detect from the domain's direction. In that case it would be
> no risk to have a U-label that starts with numbers or contains only
> numbers. Thus it may be possible to relax the current proposed rule in
> IDNA2008.
>   
This requires that applications identify correctly all instances of 
domain names - my thinking when writing -bidi was that it would be 
extremely confusing for users to have a domain name display in one order 
when in the address bar, and in another order when in running text, so I 
argued that these should be treated identically (last paragraph of 
section 6 of -bidi-02), and - based on that argument - the behaviour of 
domain names in running text was the behaviour that it was important to 
write rules for.

I haven't heard anyone argue the opposite position yet, although I've 
heard many people wistfully wish that they could make it so. Do you wish 
to reopen this argument?
>
> So my suggestion is: Those problems which cannot be almost completely
> resolved at the protocol level should be dealt with only at the
> informational level, and no rules should be specified about them in the
> protocol. One such example is to relax the BIDI rule about numbers, which
> I mentioned above.
I do not understand what you are asking here - what rule (referring to 
the numbered list in section 4 of -bidi-02) do you wish to relax, and 
which requirement in section 3 of -bidi-02 (which is the basis on which 
these rules were designed) do you think we can live without?

                          Harald



More information about the Idna-update mailing list