I was playing with the addfeature handler mentioned here https://mailman.ntg.nl/pipermail/ntg-context/2016/083952.html and run into a problem with ttc-fonts: \starttext \directlua{ fonts.handlers.otf.addfeature { name = "oneb", { type = "substitution", data = { ["1"] = "period", }, }, "feature test", } } \font\test= name:LatinModernRoman:+oneb \test 1234567890 \font\test= name:cambria:+oneb \test 1234567890 \stoptext This gives: .234567890 p234567890 So with latin modern it works fine, while with cambria the first letter of the substituation is used. The used fonts are: filename=lmroman10-bold.otf filetype=otf format=otf foundname=D:/context-minimals/context/tex/texmf/fonts/opentype/public/lm/lmroman10-bold.otf usedmethod=database filename=c:/windows/fonts/cambria.ttc format=ttc foundname=c:/windows/fonts/cambria.ttc usedmethod=direct (I have no idea why the bold version of lm is used, but I don't care now) Looking at the tma I see one difference between both fonts: glyphs in cambria have no "name". A typical entry looks like this [46]={ ["boundingbox"]={ 109, 0, 311, 232 }, ["index"]=484, ["unicode"]=46, ["width"]=420, }, while with latin modern it looks like this: [46]={ ["boundingbox"]={ 81, 0, 237, 156 }, ["index"]=88, ["name"]="period", ["unicode"]=46, ["width"]=319, }, Is is normal that glyph of ttc-fonts have no name data? If yes how should one do substituations in such fonts? -- Ulrike Fischer http://www.troubleshooting-tex.de/