-----BEGIN PGP SIGNED MESSAGE----- Martin Duerst wrote: > At 15:43 01/10/10 +0900, Soobok Lee wrote: > >From: "Martin Duerst" <[EMAIL PROTECTED]> > > > > The additional complexity introduced by reordering is a very > > > serious problem. It is true that this complexity is somewhat > > > similar to the complexity of e.g. nameprep or conversion from > > > a legacy encoding. However, on many platforms, both conversion > > > from a legacy encoding as well as many aspects of nameprep > > > are available as libraries, and are used for other purposes. > > > >Current Windows 98,2K,XP and Linux contain NFKC codes ? > > No. My personal preference would be for NFC, anyway, because > most of the additional mappings in NFKC are not really useful, > because they are from characters that are quite difficult > to type in. So these characters could just be forbidden rather > than mapped. The only exception I know is full-width ASCII, > which could either be included in the nameprep mapping step, > or could be done as a front-end 'quality of implementation' > step (similar to how the ideographic fullstop is currently > treated).
I absolutely agree with this - I've been preparing a detailed rationale for using NFC in preference to NFKC, that considers all the categories of compatibility mappings. I'll post it tomorrow. An important consideration is that by disallowing a larger set of characters, we can avoid the need for "additional foldings" - i.e. it is possible to just apply NFC and the standard Unicode case folding, in either order, which strengthens your argument above about being able to use existing libraries. > Displaying ACE when nothing else is available is acceptable > as a 'best-effort' solution. But it is very far from a good > solution, and designing the rest of IDN for this doesn't > make sense. A better solution for cases where a name can't be displayed in its original script, is to use a transliteration (which unlike an ACE encoding, has a chance of actually meaning something to end- users). I have a proposal for a new RR that allows translations and transliterations of a name to be looked up, and provides a way to encode the language and script of each name. This is a new feature that is independent of the rest of IDN; it doesn't break the basic model of DNS as an untagged namespace. - -- David Hopwood <[EMAIL PROTECTED]> Home page & PGP public key: http://www.users.zetnet.co.uk/hopwood/ RSA 2048-bit; fingerprint 71 8E A6 23 0E D3 4C E5 0F 69 8C D4 FA 66 15 01 Nothing in this message is intended to be legally binding. If I revoke a public key but refuse to specify why, it is because the private key has been seized under the Regulation of Investigatory Powers Act; see www.fipr.org/rip -----BEGIN PGP SIGNATURE----- Version: 2.6.3i Charset: noconv iQEVAwUBO9DB/DkCAxeYt5gVAQFn2Qf/TTGRpLlpuFyxZW4klkAGaGOPDF7wwsND ovDc38ypkWm3psxJ9NunKzmEudNYA8LiUxxCxU2qO3NAaYnGbqI58/DkauMhiDGK wb/LO54RcIEuRBiCBDM3R1q1Deznz04lAVudjrOAJX/OdGHTKlEg22E4PTZJPwMZ FE5deUIk5rG73dtsG/XvXuPdsHe4wwD+70LxWnu7+H5AdBDb/WoUsB0CQor3yQbu yFDcXSWof5OS4c+x1z53J/gU7I32YXWABxKABZcLHmmrjRDQmVytlMBLyYubf7yN AVtGn25eB5Y91Z53Cn5grXrd7S/lYX/ZJjAuByA3Wku/cKqu7TmkxQ== =8UbT -----END PGP SIGNATURE-----
