(Pictured: Damn metal musicians, contributing to umlaut inflation, which certainly doesn't help with this problem.)
The post on Björk got me thinking about umlaut etiquette (which could be the name of a band in another genre).
Being the dirty foreigner that I am, my first name is spelled and pronounced more or less like a common Anglo name, but with one extra letter, so I've been correcting its spelling most of my life. I don't know if I was just an obnoxious kid in this regard as well.
to get even more foreign and obnoxious, if I was to type my last name here, it would look like a misspelled Greek word with one umlaut to most readers. It is written in the following alphabet: ABCDEFGHIJKLMNOPQRSTUVWXYZÅÄÖ, which has those three extra vowels because the last three denote distinct sounds, not just variations on A and O (as opposed to the É:s and Ï's of French and the Ö's of The New Yorker). Nonetheless, attending English-language schools in other countries, most of my report cards from grade school spell my last name without an umlaut, and as they didn't have an Ä on their keyboards, I never though to complain.
NBD, right? Well, the lack of umlaut has the same effect as if you took a letter from your last name and replaced it with another one that bears some visual resemblance. My last name already has one A, so making A into A is misleading in terms of pronunciation too. Having your name spelled differently in various contexts can lead to all kinds of practical difficulties as well. Plus cultural heritage, small language etc.
(It's a part of the dark green up top, which is actually an even smaller area because that map looks like it is a projection that distorts surface areas.)
Luckily my new place of study got it correct from the beginning, despite there not being any umlauts in the Czech alphabet. I don't know if I'll ever move back to a place where they are common, so there will definitely be missing umlauts in my future to complain about if I so choose.
In what situations is it appropriate to correct people on the spelling and how would you recommend doing this without coming across as a nitpicker?