6 Maintenance Agencies

All structural metadata in SDMX is owned and maintained by a maintenance agency (Agency identified by agencyID in the schemas). It is vital to the integrity of the structural metadata that there are no conflicts in agencyID. In order to achieve this SDMX adopts the following rules:

1. Agencies are maintained in an Agency Scheme (which is a sub class of Organisation Scheme)
2. The maintenance agency of the Agency Scheme must also be declared in a (different) Agency Scheme.
3. The “top-level” agency is SDMX and this agency scheme is maintained by SDMX.
4. Agencies registered in the top-level scheme can themselves maintain a single Agency Scheme. SDMX is an agency in the SDMX agency scheme. Agencies in this scheme can themselves maintain a single Agency Scheme and so on.
5. The AgencyScheme cannot be versioned and so take a default version number of 1.0 and cannot be made “final”.
6. There can be only one AgencyScheme maintained by any one Agency. It has a fixed Id of AgencyScheme.
7. The format of the agency identifier is agencyId.agencyID etc. The top-level agency in this identification mechanism is the agency registered in the SDMX agency scheme. In other words, SDMX is not a part of the hierarchical ID structure for agencies. SDMX is, itself, a maintenance agency.

This supports a hierarchical structure of agencyID.

An example is shown below.

Figure 5: Example of Hierarchic Structure of Agencies

Each agency is identified by its full hierarchy excluding SDMX.

The XML representing this structure is shown below.

Figure 6: Example Agency Schemes Showing a Hierarchy

Example of Structure Definitions:

Figure 7: Example Showing Use of Agency Identifiers

Each of these maintenance agencies has an identical Codelist with the Id CL_BOP. However, each is uniquely identified by means of the hierarchic agency structure.