DSS2 — DDM Overview: nomenclature

According to clause 9.1.1 (c), "A region specification shall be a set of ranges." Whereas according to clause 9.1.3.1 (a), "A region specification may be created using the Create Region service." These two statements are contradictory, because the Create Region service only determines what dimensions will be in a region, not the ranges of those dimensions. The nomenclature should be clarified by clearly defining three distinct terms: region template, region specification, and region realization. A region specification is a set of ranges and, furthermore, the only way that a region specification can be created is by a federate successfully invoking the following services, in order:

1. Invoke the Create Region service (DDM Service 9.2) to create a region template with a specific set of dimensions;
2. Invoke the Set Range Bounds service (Support Service 10.32) for every dimension that was explicitly specified when that region template was created, to set the lower and upper bounds of the range of that dimension for that region template;
3. Invoke Commit Region Modifications (DDM Service 9.3) to inform the RTI about the changes to the ranges of the dimensions specified in the preceding series of Set Range Bounds service invocations, thereby resulting in the creation of a region specification.

A region template is created when a federate invokes the Create Region service. The region designator argument that is returned as a result of the Create Region service is a designator of a region template only. It is not the designator of a region specification, because the range bounds have not yet been set for all of the dimensions of the region template followed by a successful invocation of the Commit Region Modifications service for this region. Only after the Set Range Bounds service has been successfully invoked for every dimension in the region, followed by a successful invocation of the Commit Region Modifications service, is that region designator the designator of a region specification.

When a federate invokes the Register Object Instance With Region, Associate Regions For Updates, Subscribe Object Class Attributes With Regions, Subscribe Interaction Class With Regions, Send Interaction With Regions, or Request Attribute Value Update With Regions service with that region specification designator as an argument, one or more region realizations is created. These region realizations, however, do not have designators.

Clarify the text as suggested.