IEC 61970-456:2018 rigorously defines the subset of classes, class attributes, and roles from the CIM necessary to describe the result of state estimation, power flow and other similar applications that produce a steady-state solution of a power network, under a set of use cases which are included informatively in this standard. This document is intended for two distinct audiences, data producers and data recipients, and may be read from those two perspectives.This new edition includes the following significant technical changes with respect to the previous edition:- Addition of the Steady State Hypothesis (SSH) profile.- Better description of the relation between different profiles and alignment with the current nomenclature used with profiles, e.g. "data set" and "network part".- Extension of the description of the use cases.