The foaf:icqChatID property relates a foaf:Agent to a textual identifier assigned to them in the ICQ Chat system. See the icq chat site for more details of the 'icq' service. Their "What is ICQ?" document provides a basic overview, while their "About Us page notes that ICQ has been acquired by AOL. Despite the relationship with AOL, ICQ is at the time of writing maintained as a separate identity from the AIM brand (see foaf:aimChatID).

See foaf:OnlineChatAccount (and foaf:OnlineAccount) for a more general (and verbose) mechanism for describing IM and chat accounts.