Comment 3 for bug 1318812

Sure, the "Custom words" screen could temporarily have its parent item below the current "Spell checking" switch.

I agree with the idea of having a global custom dictionary. Multilingual people code-switch between sentences or even in the middle of a sentence. The spell-checker might be able to tell which language you're using currently if you're using all standard words -- but if you're introducing a custom word, maybe you just switched to another language, or maybe you didn't, so the word would end up in the wrong custom dictionary too often. And a single custom dictionary also makes for a much simpler UI.