1. A method operating in a computer system for managing execution of licensed software items in said computer system, comprising the steps of: maintaining by said computer system a store of license authorizations for said software items; each license authorization including an indication of license management policy for a software item, said indication being in the format of an encoded document of a data type consisting of an ordered sequence of three elements, the three elements including a document descriptor, a document header and the document content; accessing by said computer system said store to retrieve information from said license authorization for said software item, in response to a request from a client, and comparing said client request, including identification of said client and said software item, with said retrieved information, to produce a grant or refusal of said request.