The foaf:msnChatID property relates a foaf:Agent to a textual identifier assigned to them in the MSN online Chat system. See Microsoft's the MSN chat site for more details (or for a message saying "MSN Chat is not currently compatible with your Internet browser and/or computer operating system" if your computing platform is deemed unsuitable).

It is not currently clear how MSN chat IDs relate to the more general Microsoft Passport identifiers.

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