Steps to reproduce:
- go to settings/external accounts
- click on "mediawiki"
- click through the OAuth permission screen on mw.org
- the bold text is phrased in a confusing way: I can't tell if "mediawiki" is the username or the site name or the provider name
- account ID instead of account name
- the link is unreadable and completely broken (clicking it gives you a "Bad Request" error), probably URL encoded twice
- also, why not use nice URLs?
All in all, I have no idea whether linking the account was successful; if I had a username with lots of non-ASCII chars, I couldn't even tell if it's indeed my account that's about to be linked.

