IEC/TR 61850-90-1:2010(E) provides a comprehensive overview on the different aspects that need to be considered while using IEC 61850 for information exchange between substations. In particular, this technical report defines use cases that: - require an information exchange between substations; - describes the communication requirements; - gives guidelines for the communication services and communication architecture to be used; - defines data as a prerequisite for interoperable applications; -describes the usage and enhancements of the configuration language SCL.