3.3 Scope of Energy Interoperation Communications While the bulk of examples describe the purchase of real power, emerging energy markets must exchange economic information about other time-sensitive services For example, delivery of power is often constrained by delivery bottlenecks. The emergence of distributed generation and plugin Electric Vehicles (PEV) will exacerbate this problem. EMIX includes product definitions for tradable congestion charges and transmission rights. Locational market prices in distribution may come to mirror those already seen in transmission markets. Other services address the direct effects of distribution congestion, including phase imbalances, voltage violations, overloads, etc. These market needs introduce different market products, yet the roles and interactions remain the same. Intelligent distribution elements, up to an intelligent transformer, could be sometimes a VEN, sometime a VTN. A description of the tariffs or market rules to support these interactions is outside the scope of this specification. The interactions patterns were developed to support them in markets in which they are required.