[arabic-vip] [vip] Overarching principles used in Devanagari team report

[Andrew Sullivan]

On Wed, Sep 21, 2011 at 10:44:43PM -0700, Sarmad Hussain wrote:
>  
> 
> 200C (ZWNJ): Even though there may be some policy to restrict the use of
> ZWNJ in the TLDs, the committee felt that due to its critical use in Arabic
> script to separate ligatures which end with joining letters, there is a need
> for ZWNJ by the community for TLDs (even though there may be limited use at
> this time).  Zero Width Non Joiner is needed in domain names in Arabic
> script to separate multiple words within a label.  
> 
>  
> 
> Though there is a defined rule which allows ZWNJ only in contexts where its
> effect is visible, there are few contexts which ZWNJ may still not have a
> visible impact.  This includes characters U+0637, U+0638 and U+069F.  This
> is indicated by the two sequences, one with and one without the ZWNJ:  طب
> ط‌ب.  The ZWNJ should not be permitted following these three characters, in
> addition to the constraint already put on its use by the IDNA 2008 protocol
> (see RFC 5893).
> 

I think that the above, particularly the latter point, was indeed part
of the discussion in Doha.

I might suggest adding some additional text.  Perhaps the following
reflects the team members' view:

    It is impossible to ascertain whether every font and every writing
    style will make the ZWNJ visible everywhere it might appear.
    Nevertheless, the team believes that the IDNA2008 CONTEXTJ rules,
    plus the restriction that ZWNJ not follow U+0637, U+0638, and
    U+069F, will be enough to prevent confusion.

?

Alternatively, 

    It is impossible to ascertain whether every font and every writing
    style will make the ZWNJ visible everywhere it might appear.
    Nevertheless, the team believes that the IDNA2008 CONTEXTJ rules,
    plus the restriction that ZWNJ not follow U+0637, U+0638, and
    U+069F, should in principle be enough to prevent confusion.  It
    might be prudent to undertake more exhaustive studies of this in
    actual systems in order to verify that deployed systems work as
    expected.

Best regards,

A


-- 
Andrew Sullivan
ajs at anvilwalrusden.com