I'm starting to think that it might actually be better to move away from codes, to avoid things like the 401/403 confusion.

How about we rename our pages to:

- permissiondenied (permissiondenied.html)
- notfound (notfound.html)
- error (error.html)
- unavailable (unavailable.html)
- maintenance (maintenance.html)

and put them together into an `errors` folder in /ui ?