This standard is part of a proposed set of standards for DIS applications. Each standard in the proposed set describes one or more of the several elements that constitute the DIS environment. As a whole the set of standards will define an interoperable simulated battle environment. This particular standard addresses the entity information and interaction protocols. This standard defines the data messages@ known as PDUs@ that are exchanged on a network between simulation applications. The messages defined are for interactions that are primarily within visual range. This standard does not provide information to support other DIS application requirements@ such as electronic combat.