Research about plans and resulting guidance for practice tend to focus on making one plan and implementing it. Plans are made and used, however, by many autonomous agents, a variety of organizations pursuing their interests while recognizing interdependence with the activities of other agents. Expanding the focus beyond one plan by one organization to many plans by many organizations raises three questions. With what agents should I make plans? How should I use plans to communicate strategically among agents? How should I express the content of such plans? We consider these questions by interpreting plans as signals, information shared among organizations. We contrast this perspective on plans with other interpretations of planning and elaborate responses to the three questions using examples from practice. By considering these questions explicitly, planners can take advantage of the signaling effects to increase the potential effectiveness of making and using plans.