Six places in the Firefox code base use the word "firt" instead of "first". One uses "firth" instead of "fifth". "Firth" is apparently a real word, used to describe certain bodies of water in Scotland. en.wikipedia.org/wiki/Firth

I just found 4 places where we use "detroyed" instead of "destroyed". I haven't looked it up, but I'm pretty sure detroyed is what happened to Community season 5 when Troy left.

I just tried grepping our codebase for each entry in the first column of searchfox.org/mozilla-centra… and ogod we are torrible at spelling

Man, I'm always spelling "apennines" as "apenines".

I'm always tempted to r- patches for that typo but can't bring myself to do so.