I did not realize that a few English words (such as "coöperate" and "reënter") were sometimes (rarely, but sometimes) still written with a diaeresis (or diacritic), that is, an umlaut indicating the separation of vowels. I discovered this today when I snagged a back copy of the New Yorker from the communal magazine pile at work and, in the middle of the Alice Munro story "Corrie," came across the word "reënter" printed in exactly that form. I might have just written it off as an error, but I was feeling obsessive and gloomy about details today, so it bothered me. Besides, seconds before I had somehow completely misread a cartoon involving a lawn's inner monologue on self-worth and the appearance of a phantom accent mark right after that just annoyed me. Since it appeared to be real, I decided to investigate.
My first thought on the matter was that maybe it was some kind of weird Canadian accent, since Alice Munro is Canadian. It didn't seem likely that The New Yorker would integrate that into their printing of the story, but I wanted to check anyway, so I ended up searching for something along the lines of "canadian english accent reenter umlaut." I just kept typing and typing until there were no more results, because that is how I do a Google search. I did not seem to come across anything relevant at any part of the process. So then I searched for something like "alice munro corrie new yorker misprint error crap thing my cat likes fishies" and the results just got more and more general. But simply looking up "umlaut" on Wikipedia proved to be a better use of my time.
I've read hundreds of issues of the New Yorker and never noticed this before. I might have seen an example of it and just thought it was a misprint, or I might have never come across an example because even if the New Yorker does this is a rule, the number of words that have a repeating vowel hiatus are relatively rare. Oh well, I just hope you don't think I'm naïve.
ALT + 137 = ë ALT + 139 = ï ALT + 148 = ö
If you have a Mac, try yelling and banging your head against the keyboard. Something might happen.
Or try Option + U, then release and hit whatever vowel you want the umlaut to appear above. ☺ (ALT + 1)