What does QQ means?

Hello, when i want to register at swsro. i need to fill in (QQ) What does that mean? :)

QQ is a chatting thingy like msn, but you use numbers instead of an mail....
just write random numbers thats 6--10 numbers long
like: 19682769

[Only registered and activated users can see links. Click Here To Register...] or choose a random number(6-9 numbers).

okay thank you :)