Dear list, I have just copied this from https://www.pragma-ade.com/general/manuals/languages-mkiv.pdf#page=23: \startluacode local subset = { a = true, e = true, i = true, o = true, u = true, y = true, } languages.hyphenators.traditional.installmethod("test", function(dictionary,word,n) local t = { } for i=1,#word do local w = word[i] if subset[w] then t[i] = { before = "<" .. w, after = w .. ">", left = false, right = false, } else t[i] = false end end return t end ) \stopluacode \definehyphenationfeatures [demo] [alternative=test] \setuphyphenation[method=traditional] \starttext %\righthyphenmin=-1 \sethyphenationfeatures[demo] \hsize\zeropoint coming anaback \stoptext Using current latest (from 2023.02.07 19:06), I get: c<o o>ing an<a a>ack I’m missing m and b in the hyphenated words. I’m afraid that the hyphenator is all Greek to me. Is there any reason why letters are lost in hyphenation? I’m afraid (I think) I might have hit a bug. Many thanks for your help, Pablo