1. A query resolution system comprising one or more archives containing a plurality of persistent data entities, each entity including metadata in the form of a group of properties having property values assignable thereto, at least some of those properties providing a definition of a predetermined level of scope such that within a set of related data entities, the scope of an entity at a higher level encompasses the scope of related entities at a lower level of scope, a registry database operable to extract from said one or more archives those data entities having predetermined properties including said definition of a predetermined level of scope and a query resolution engine operable in response to a request from a query interface to identify extracted entities whose property values fulfil the request.