ZWNJ and CONTEXT

[John C Klensin]

--On Tuesday, 08 April, 2008 13:03 +0430 Alireza Saleh
<saleh at nic.ir> wrote:

> Dear Ken ,
> 
> Yes I got your points, I also talked specially with John to
> include ZWNJ which is a necessary for Persian,Now it will
> going to be available, but at least we need to make it in a
> safe way which doesn't make confusion problem or very big
> backward incompatibility to the current implementation of IDN
> for Persian language. Most of the problems can be resolved at
> the registry level but some of the are out of scope of the
> registry and would be useful if we can find a very good
> support of them within the protocol if required. Would it be
> possible to have any rule in CONTEXT(J/O) to address
> combination of individual characters as well as the current
> suggestion which works around category of them.

It is possible to have almost any rule.  However, these rules
will need to be examined by every registry and every client
doing lookup (and maybe some others), even those that don't
operate in an Arabic environment.   So we have an engineering
problem in which making a test that is more simple has
significant operational advantages even while making a test that
is more precise lowers risks and has similar advantages.

We will need your continuing advice, and that of others, to help
determine how to best balance that tradeoff.

 best,
    john