Yeah, I noticed that but I have a azerty keyboard coz I'm in France and so I can also do é,è ç à and even ê as well as ä - what a repertoire, eh?!
E
<Added>oh, what it means - it's a pronunciation thing (but I did it by mistake)- I think it lets you read two vowels separately as in Anaïs (Anay-ees) rather than Anais (Anace)