The UK Ministry of Defence (MOD) has very clear requirements for registering individual components of XML schemas, relating them to definitions in a data dictionary and re-using these components in schema documents defining individual document types. In doing this, careful version management is required.

During 2003, a simple mechanism was put in place to achieve this. This used text documents to hold the schema components, links between these text documents and an existing data dictionary, and a means to build schema documents containing the correct version of each component definition.

Using this as a prototype, the MOD is working with three OASIS Technical Committees to define a standards-based mechanism to combine registry, repository and content assembly mechanisms in a way that meets both its own needs, and the wider UK Government need. The intention is to define a system allowing management of schema components and related metadata with standards-based interfaces that allow a fully federated system to operate across the complete public sector. This could, in turn, be adopted by other Governments and organizations, so putting in place a practical mechanism to re-use standard data definitions such as those being defined in other OASIS TCs.

The requirements include:

· registering proposed schema components as drafts;

· reviewing proposed schema components;

· registering approved schema components;

· assembling complete schemas from components; and

· managing the lifecycle of the components and schemas.

At the time of writing this abstract, the study is just starting, involving the MOD, the OASIS e-Government TC, ebXML Registry TC and the Content Assembly Mechanism TC. By the time of the conference, a paper study will have been completed. This is likely to lead to a solution based on open-source software.