the essentials of comprehensible specifications of business and of system artefacts ought to be used by, and therefore understandable to, all customers of these specifications - business subject matter experts, decision makers, analysts, it architects and developers. these documents have to be understood in the same manner by all stakeholders. and, as c.a.r. hoare observed, only abstraction enables a chief programmer or manager to exert real technical control over his teams, without delving into the morass of technical detail with which his programmers are often tempted to overwhelm him. the book brings together theoreticians and practitioners to report their experience with making semantics precise, clear, concise and explicit in business specifications, business designs, and system specifications. it includes both theoretical and very pragmatic papers based on solid and clearly specified foundations. these seemingly different papers address different aspects of a single problem - they are all about understanding of business enterprises and of information systems (computer-based or not) that these enterprises rely upon. a substantial number of papers demonstrate that good business (and it) specifications ought to start with the stable basics of the relevant business domains, thus providing a foundation for describing and evaluating the details of apparently always changing requirements.