[XeTeX] %18 or 18% : incorrect placement of the percentage sign ?

[François Charette]

Steffen Wolfrum a écrit :
> I have often seen (in arabic newpapers) the percentage sign set left  
> to the number "% 18".
> Recently I read an article (http://sehstoerung.sonance.net/pdfs/ 
> TitusNemeth_dissertation.pdf) that calls this "... the incorrect  
> placement of the percentage sign".
>
> Any native arabic speaker out there? Is it %18 or 18% ??
>
>   

I am not a native speaker of Arabic (though I doubt most native speakers 
would know the answer), and my knowledge of the language is more 
specialized in its classical and medieval manifestations. The author of 
that dissertation may of course be right that the percentage sign should 
be set at the right ("18%" or "١٨٪"), perhaps because it is somehow 
"semantically embedded" within the numerical sequence, which is 
displayed from left to right in Arabic. It would be interesting to know 
whether any manual of Arabic typography has something to say on this 
matter. But standard usage really seems to be the opposite. On 
ar.wikipedia.org it is always at the left, either as % or as U+066C (٪). 
I have also checked BBCArabic.com and there they avoid the problem by 
systematically using بالمائة instead of the percentage sign ;)

François