Le sam. 6 janv. 2024 à 11:56, Corentin <corentin.jabot@gmail.com> a écrit :

It is very surprising to me that ZWJ is opt-out rather than opt-in given the security implications and the fact supporting them requires implementation of TR39 3.1.1.

I suppose this was done to better support Sanskrit?

This is because ZWJ and ZWNJ are needed orthographically in modern languages (Persian being one of them, see the example in Section 5.1.3 of UTS #55), and because this does not actually change the picture as far as security implications are concerned: the 260 variation selectors have always been allowed (and must always remain allowed), and those even more rarely have a visible effect.