Special case for Bidi in draft-ietf-idnabis-protocol-14

Andrew Sullivan ajs at shinkuro.com
Mon Sep 7 17:16:07 CEST 2009

On Mon, Sep 07, 2009 at 06:49:55PM +0900, "Martin J. Dürst" wrote:
> I agree with Mati. I think in protocol, checking the BIDI constraints 
> should just be a MUST. BIDI then can say (as it already does) that these 
> constraints are essentially irrelevant for LTR-only domain names.

I can think of a case where not checking BIDI rules would be
justified.  Suppose a system is configured such that it is impossible
to enter RTL characters, and there are no fonts for displaying RTL
characters either.  In this case, actually performing the BIDI check
would just be a waste of cycles: they're effectively impossible
anyway.  (The purpose of the BIDI rule, after all, derives primarily
from the display characteristics of RTL versus LTR.  Therefore, if no
RTL is possibly displayed, then there are no display characteristics.)

Such a clear exception justifies a SHOULD, I think.  I am, however,
not wedded to this position.


Andrew Sullivan
ajs at shinkuro.com
Shinkuro, Inc.

More information about the Idna-update mailing list