Same goes for airline tickets. When you buy a ticket, the travel agency says that you should write your name exactly as in your passport, but on the ticket and boarding pass they then change it: Hyphenation is removed as well as accents.
What counts as accent vs letter depends a lot on the language. For example, in German the umlauts are considered own letters and not accented vowels, in Spanish ñ is considered an own letter and not an accented n etc.
