Often the process and effort in building interoperable Command and Control (C2) systems and simulations can be arduous. Invariably the difficulty is in understanding what is intended. This paper introduces the notion of combridges as a means to help transition abstract ideas or concepts into concrete implementations. We examine the key elements to achieve composability, which include the direction provided by a process, the importance of a conceptual model, the use of patterns to help characterize reusable aspects of a design, the importance of having good discovery metadata and well-defined interfaces that can be implemented, the use of components, and the practical use of libraries and tools. We suggest that, of all these elements, a properly documented conceptual model provides the basis for formulating a composable bridge, and that things like patterns, discovery metadata, and interfaces play a key role. We take a look at a specific standard known as the Base Object Model (BOM) an...