Dear list, LuaTeX contains the library slnunicode for withing with Unicode strings. This library seems abandoned [1] and contains hard-coded data [2] that were extracted from the file `UnicodeData.txt`. By comparing [3] this data to files `UnicodeData.txt` from various versions of the Unicode standard, I concluded that they originate from Unicode 3.1 (released in March 2001). I am not sure if the LuaTeX team applies any patches to slnunicode but if not, then that's quite old! The good news is that updating the hard-coded data to the latest Unicode standard seems trivial and can be done using an automated script [4]. The bad news is that there were many changes to the Unicode standard since version 3.1 and broader changes may be necessary to bring the package up-to-date. [1]: https://github.com/LuaDist/slnunicode [2]: https://github.com/LuaDist/slnunicode/blob/master/slnudata.c [3]: https://github.com/Witiko/markdown/pull/557#issuecomment-2983818188 [4]: https://spacegit.unibe.ch/bela/mb-linux-msli/-/blob/38b8bc2d8ee86a6c4d0d8334... Best, Vitek