[XeTeX] Unicode space characters

[Will Robertson]

On 2009-03-18 18:21:38 +1030, Arthur Reutenauer 
<arthur.reutenauer at normalesup.org> said:

>> I remember some people talking about this before but as far as I know
>> nothing came of it; to my knowledge this is the first time a
>> comprehensive set of definitions has been created.
> 
>   We had a discussion in August 2007 but it didn't lead anywhere,
> indeed.
> 
>   And now I think about it, it was on the ConTeXt list :-)

Couldn't have been -- how would *I* remember it, then?  :)
This must have come up a couple of times.

W