This document provides guidelines for smart grid interoperability. This guide provides a knowledge base addressing terminology, characteristics, functional performance and evaluation criteria, and the application of engineering principles for smart grid interoperability of the electric power system with end use applications and loads. The revision will focus on updating the information related to the distribution, transmission, service provider and customer domains. Additionally, the application of the IEEE Smart Grid Interoperability Reference Model (SGIRM) framework may be simplified based on practical experience.