Dear list, The EB Garamond font is lacking the ϵ glyph but it contains ε. So naturally you want to remap ϵ to ε. It cannot be done using font features because the the slot 0x03B5 (ϵ) is just missing, so substitution will not kick in. I tried adapting the mechanism to add uppercase greek to Latin Modern Math from lm- math.lfg. Unfortunately, my code is not working. What am I doing wrong? Cheers, Henri --- \startluacode local patches = fonts.handlers.otf.enhancers.patches local function patch(data,filename) local uni_to_ind = data.map.map if not uni_to_ind[0x3F5] then patches.report("add ε for ϵ") uni_to_ind[0x3F5] = uni_to_ind[0x3B5] end end patches.register("after","missing glyphs","^ebgaramond*", patch) \stopluacode \setupbodyfont[ebgaramond] \starttext ε % = 03B5 ϵ % = 03F5 \stoptext