A basic game constraint is that there is no default means for players to communicate with eachother. Bodies can communicate in limited ways unless a high degree of intimacy is acheived. But play and signalling should be interactive enough to allow trust, attraction, rivalry, and enmity to develop without language. On the other side however the effects of toxic behaviour is meant to be blunted. It is possible to communicate through all four of the senses in the SIA. * signals
Signals are generic types of message that broadcast a topic or an imperative but cannot easily form syntax.
Messages are linguistically complete, though they may be constrained. Only bodies with a minimum level of intimacy and trust can exchange messages.
Both signals and messages can be used to signal or deceive.
You should be able to send signals or sets of signals to indicate belligerence, submission, dominance, strength etc.
Individual bodies can have special skills at decoding certain signals more or less than others. You can fool some of the bodies all of the time or all of the bodies some of the time sorta thing...
Signals can be honest or deceitful or ambiguous or otherwise.