Many keyboard layouts use the right alt as the AltGr key for additional characters like language-specific letters or currency symbols (or at least many European ones do).

As for the right ctrl, by association with the AltGr, I usually map it as the Compose key.

Still much better when it fails at the first step. I once got myself in a bit of a struggle with Windows 10 by using "ł" as part of Windows username. Amusingly/irritatingly large number of applications, even some of Microsoft's own ones, could not cope with that.

I got curious if I can get data to answer that, and it seems so.

Based on xlsx from [0], we got the following ??d? localities in Poland:

1 x Bądy, 1 x Brda, 5 x Buda, 120 x Budy, 4 x Dudy, 1 x Dydy, 1 x Gady, 1 x Judy, 1 x Kady, 1 x Kadź, 1 x Łada, 1 x Lady, 4 x Lądy, 2 x Łady, 1 x Lęda, 1 x Lody, 4 x Łódź, 1 x Nida, 1 x Reda, 1 x Redy, 1 x Redz, 74 x Ruda, 8 x Rudy, 12 x Sady, 2 x Zady, 2 x Żydy

Certainly quite a lot to search for a lost package.

[0]: https://dane.gov.pl/pl/dataset/188,wykaz-urzedowych-nazw-mie...