I checked the \catcode of ^^^^200d, it is 12. As for \XeTeXcharclass and \XeTeXinterchartoks they are used in bidi.sty but not for 200d
I have found other pattern files where 200d is used, for example in Assamese: \patterns{ % GENERAL RULE % Do not break either side of ZERO-WIDTH JOINER (U+200D) 22 % Break on both sides of ZERO-WIDTH NON JOINER (U+200C) 11 % Break before or after any independent vowel. অ1 > Le 25 mars 2021 à 13:26, Zdenek Wagner <zdenek.wag...@gmail.com> a écrit : > > I do not see how polyglossia could do it, maybe it can change its > \catcode and you could display the value. It might use it in > XeTeEcharclass and XeTeXinterchartoks but I am not sure whether these > can be displayed by \showthe <http://www.imt-atlantique.fr/> Yannis HARALAMBOUS Professor Computer Science Department UMR CNRS 6285 Lab-STICC <http://perso.telecom-bretagne.eu/yannisharalambous/> <https://twitter.com/y_haralambous> <https://www.linkedin.com/in/yannis-haralambous-5529073?trk=hp-identity-name>Technopôle Brest-Iroise CS 83818 29238 Brest Cedex 3, France Une école de l'IMT <http://www.imt.fr/> Comme on dit dans mon pays, c'est de l'identification, sans en être, tout en en étant (Raymond Queneau)