I do not have an official transliteration but a better question could be: Is it legally okay to use unaccented letters of Romanized languages like French, double letters like the Nordic "ae"; or is there a different legal condition for each country?

Feb 16, 2021, 21:59 by eliz@gnu.org:
Date: Tue, 16 Feb 2021 19:55:13 +0100 (CET)
Cc: Emacs Devel <emacs-devel@gnu.org>
From: xenodasein--- via "Emacs development discussions." <emacs-devel@gnu.org>
> Please use your full legal name (in ASCII characters) as the subject
> line of the message.
Hello Lars,
What is the process for citizens of countries with non-ASCII legal names?

Can you transliterate the name in ASCII characters?
If not, we will need to ask the copyright clerk for instructions in
this case.

Thanks.