Le sam. 6 janv. 2024 à 15:56, Robin Leroy <eggrobin_at_[hidden]> a écrit :

> Le sam. 6 janv. 2024 à 11:56, Corentin <corentin.jabot_at_[hidden]> 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
>> <https://www.unicode.org/reports/tr39/#Joining_Controls>.
>> 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 <https://www.unicode.org/reports/tr55/#General-Security-Profile>),
> and because this does not actually change the picture as far as security
> implications are concerned: the 260 variation selectors
> <https://util.unicode.org/UnicodeJsps/list-unicodeset.jsp?a=%5Cp%7BVariation_Selector%7D&g=&i=xid_continue>
> have always been allowed (and must always remain allowed
> <https://www.unicode.org/policies/stability_policy.html#Identifier>), and
> those even more rarely have a visible effect.
>
See also the more verbose rationale in Section P/(A) on page 5 of L2/22-229R
<https://www.unicode.org/L2/L2022/22229r-prop-changes.pdf>, as well as the
review note under #31/2(C) on page 12.
The relevant decision is UTC consensus 173-C29
<https://www.unicode.org/L2/L2022/22241.htm#173-C29> with action item
173-A125 <https://www.unicode.org/L2/L2022/22241.htm#173-A125>.