Hi, I am developing an OpenType font with the following cursive feature. feature curs { lookup cursivejoinrtl; # RIGHT_TO_LEFT flag set between Hah, Meem, Yeh and final Meem lookup rehwawcursive; # RIGHT_TO_LEFT flag clear between Waw and Hah } curs; Here is the rendering of the word وحميم in TextEdit. Using HarfBuzz I got the following result. The same rendering problem occurs when using Safari. It seems that is related to Core Text. I reported the issue to Feedback Assistant over a year ago but haven't had a response yet. So I'm posting the problem on this forum. Any support on this matter would be greatly appreciated.