In all communicating multiagent systems, and particularly in domains that include agents built by different designers, there must be some set language and protocol for the agents to use when interacting. Independent aspects of protocols are information content, message format, and coordination conventions. Among many others, existing language protocols for these three levels are: KIF for content [29], KQML for message format [28], and, more recently, COOL for coordination [8]. There has been a lot of research done on refining these and other communication protocols. MAS designers must carefully consider what features in a communication protocol are needed in a given domain.