Since there is a single communication channel, agent 
hears
messages sent by all agents whether or not they are intended for it.
Messages sent by agents from another team are completely ignored.
Messages sent by a teammate are identified by the
<team-identifier> field. Since all team members know the
locker-room agreement, agents monitor all messages from teammates to
determine their teammates' internal states, even if the content of the
message is intended for another teammate.
Agents can distinguish messages that are intended for them by checking
the <team-identifier> and <target> fields. An agent 
pays attention to a message from a member of the same team that is
targeted to 
, to the entire team, or to some subset of the team
that includes 
. The <target> field could identify an
individual agent either by its unique ID number or by the role that it
is currently playing. Thus, a message could be sent to the agent
playing a particular role without knowing which agent that is.
Similarly, a message could be targeted towards all agents in a unit
of the team's current formation.