BIDI rules

[Alireza Saleh]

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


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.


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.



Alireza