but if we support such a thing, we need a better specification; there are probably more space related chars that needs treatment then
There's not much to it, actually. There are some space characters in Unicode, and we should handle them as much Unicode-compliantly as possible; and there are some particular typographic conventions on top of that, for each language. It's easy to come up with a simple scheme to support both, and I've already outlined it on a different mailing-list (http://tug.org/pipermail/xetex/2008-February/008529.html). The problem is to decide how much of the users' old typing habits we want to take in account (and, Olivier, another message by me in the same thread addresses the exact same issues you were raising a few days ago: http://tug.org/pipermail/xetex/2008-February/008533.html). I can discuss that with you at BachoTeX, Hans. It's best done around a beer or two, anyway ;-) Arthur