[quote=@Cyclone]
Huh. So piss off an elf and receive a day long scolding, I suppose?

Piss off a Tinite and get stabbed. At least some of them have the decency to stab you in the front, though.
[/quote]More or less,  at least when you deal with people who are fluent in old elvish.
Generally though they can get into cursing spree if you pissthem  off. Except it sounds almost melodious and they don't use any swear words.  They use elaborate  terms and implications so unless you have profound experience with elves you may even miss that they pretty much called you the lowest scum on Earth.
Diplomats from Yllendthyr at times do the same,  except they  tell it to you on your own language.
Albeit elves of Yllendthyr kinda also built up a bad reputation on this and more savvy foreigners may assume that anything that derails from the topic is most likely a hidden elven insult.