my comments on draft-ietf-idnabis-bidi-05

"Martin J. Dürst" duerst at
Mon Sep 7 09:11:37 CEST 2009

Hello Mati,

On 2009/09/07 15:47, Matitiahu Allouche wrote:
> On October first, Martin J. Dürst asked:
> conditions 2/4: Why are BN (control characters) allowed in RTL but
> not in LTR?
> BN characters are invisible and should be banned as allowing phishing and
> violating the Label Uniqueness requirement.  However, ZWJ and ZWNJ are
> classified as BN, and ZWNJ is required for the proper orthography of
> Persian which is written with the Arabic script, hence BNs are allowed in
> RTL labels.

That makes a lot of sense. But then shouldn't BN also be allowed for 
LTR, because some of these characters are needed in Indic scripts?

Regards,   Martin.

> Shalom (Regards),  Mati
>             Bidi Architect
>             Globalization Center Of Competency - Bidirectional Scripts
>             IBM Israel
>             Phone: +972 2 5888802    Fax: +972 2 5870333    Mobile: +972 52
> 2554160

#-# Martin J. Dürst, Professor, Aoyama Gakuin University
#-#   mailto:duerst at

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