You might be surprised how often this comes up for professional writers and editors.
Bryan Garner, the ace lawyer & editor & language authority, explains:
The more arcane or technical a loanword, the more likely it is to retain a foreign plural, diacritical marks, and italics. The more common it becomes, the more likely it is to lose them.
Corollary: If the loanword becomes widespread, it is most likely to lose italics first, then diacritical marks second, and a foreign plural last.
You should bookmark Garner’s delightful and erudite blog.
