Currently, when defining a font feature one has to enable all features by hand which is IMHO not very user friendly as it implies prior knowledge about OpenType font features and the meaning of each one, not every Arabic user, for example, knows what does 'init', 'medi, etc. ligatures mean yet to know that he must enable them to get proper font rendering. I think some font features should be on by default, so that \definefontfeature[script=arabic] should be enough to get an Arabic font rendered correctly with the default features as its designer intended (designers assume that certain will be on while other are off by default, like liga vs. dlig), and if some one wants to disable a certain default feature he can turn it off, not the reverse. Microsoft's OpenType features list page (http://www.microsoft.com/typography/otspec/features_ae.htm) gives a "UI suggestion" for each feature noting if it should be on by default, I think those are what most OpenType enable by default (at least the ones I tested). Regards, Khaled -- Khaled Hosny Arabic localizer and member of Arabeyes.org team