Tag interactions are agent interactions that complement and differ from speech act communication models. Tags are public information that agents expose to others in the system to allow two types of interactions. Tag monitoring interactions let agents observe the tags of others actively. Tag fortuitous interactions make agents realize the tag of others with unrequested and application-dependent messages. In this paper we model tag interactions based on the agent environment and computational bodies to enact, maintain, and regulate their execution. We discuss the model and we identify further issues in the current state of the research. An example application is described in detail to show the potential of introducing tag interactions.