test code:

\starttext

\showotfcomposition{file:uthmanichafs1ver09.ttf*arabic}{r2l}{١} \page \showotfcomposition{file:uthmanichafs1ver09.ttf*arabic}{r2l}{١ ١} \page \showotfcomposition{file:uthmanichafs1ver09.ttf*arabic}{r2l}{١١} \page

% \usemodule[fonts-coverage] % \showfontcomparison[list=file:uthmanichafs1ver09.ttf]

\stoptext

Thank you very much, Hans! Now all issues with this font are solved (new issues within my actual project will surely follow, but no font-issues, I hope). I have to say once more, that I never had experienced before a such fast and competent software-support, that is at least as valuable as the software itself is! To your comments: Ok, yes, it is not a really normal font. It is specially designed for typesetting the holy quran (which is really no easy work). And there is so absolutely no problem that ALL numbers are mapped to ligatures -> there are no digits in the text of the holy quran :) (all numbers are written out at that time). Thanks again! Huseyin