Application domain description precedes requirements engineering, and is the basis for the development of a software or information system that satisfies all expectations of its users. The greatest challenge in this area is the evolution of the application domain itself. In this paper we address this problem by explicit consideration of application cases that are defined by user profiles and intentions and the system environment, i.e. scope and context. User profiles and intentions are captured through the concept of persona. We show how the application domain description can be mapped to requirements and discuss engineering of application domain descriptions. 1 Modelling Information and Software Systems Information Systems are software systems with a focus on operating on data and thus the information they provide. Typically, the engineering of Information Systems (or software systems in general) is divided into several phases, the first of which being requirements engineering. Howev...