Protocols/OSCAR
OSCAR stands for "Open System for Communication in Realtime", and while originally and ironically was not open, today it is. Originally used by AOL's AIM and ICQ products, but later discontinued, it now has had a rebirth of sorts and is used by third party services.
Sometimes, inaccurately, within the ICQ community it's called "protocol v7/8/9" but this is inaccurate. Additionally the newer [[web-based Protocols/API|API] has been called ICQ v10 by a few. These version numbers are not accurate and typically come from the rendezvous/direct connection protocol version numbers.