Recommendation ITU-T Z.151 defines the User Requirements Notation (URN) intended for the elicitation, analysis, specification, and validation of requirements and of business processes. URN combines modelling concepts and notations for goals (mainly for non-functional requirements and quality attributes) and scenarios (mainly for operational requirements, functional requirements, and performance and architectural reasoning). The goal sub-notation is called goal-oriented requirements language (GRL) and the scenario sub notation is called use case map (UCM).