This representation is very simple. JADE provies static constants defined in the class jade.lang.acl.ACLMessage. The constants are just ints, once for each ACL message communicative act. For example,
ACLMessage.INFORM
ACLMessage.REQUEST
ACLMessage.QUERY_REF
ACLMessage.CFP
etc.
These constants are used in message constructors, message templates, and in numerous if statements.
Do not confuse these communicative acts with protocols, REQUEST is not the same as FIPA-REQUEST. REQUEST is a single communicative act. FIPA-REQUEST is a sequence of commuicative acts between agents.