Dear Frederik, thank you for your answer! Why would an alternate version get a unicode value? It’s not allowed to provide two glyphs with the same unicode value. Thinking from a typesetting point of view: which one should it take? I see, so … there’s no problem here, but it’s actually right that the alternates named e.g. A.alt or A.ss01 don’t have the same unicode value as A itself … thank you for clarifying this. I would recommend you to write an OpenType feature to switch the A to the alternate A.ss01 in InDesign: I see! So it seems I’ll try to read the Robofont page on features and the documentation from Adobe and then I can hopefully figure out what to write in that feature file as now it’s completely empty. I mean, maybe this feature files needs to have lines like the following: # Script and language coverage languagesystem DFLT dflt; languagesystem latn dflt; And afterwards I could manually add what you proposed for A–Z and 0–9 in ss01, ss02, and ss03. feature ss01 { sub A by A.ss01; # ... } ss01; I saw something like A.alt in some free and open source .ufo files and was wondering what it is, i.e. why would I write .alt instead of some styleset like .ss01 … EDIT: I just discovered an article about opentype features on i love typography dot com which lists features like aalt “All alternates“, calt “Contextual alternates“, salt “Stylistic alternates”, et cetera (which I already know from CSS). So I think for another stylistic version of the figures 0–9, salt would be a kinda semantically correct feature name.