The topic elements in this document are designed to serve as published subject indicators for topics declared in other topic maps whose subjects are the same as the subjects of these topic elements. In the referencing topic maps, the addresses used to refer to these topic elements must use the unique identifiers (i.e., the “URI” values indicated within the occurrences) of these elements, because their unique identifiers are permanent; their relative positions in the document are not necessarily permanent. Addressing may use indirection via a topic element. The subjects of these published subject indicators are described in the XTM 1.0 Specification as “mandatory,” that is, conforming applications must be capable of supporting the use of these subjects as described in the XTM 1.0 Specification. The subject indicators referenced by these topic elements are the portions of the XTM 1.0 Specification that provide their normative descriptions. Other topic maps should normally use these topic elements as the identity points of these subjects, rather than the subject indicators that they themselves reference. These topic elements may be edited, at some future date, in such a way as to provide additional subject indicators that will refer to any portions of future versions of the XTM Specification that describe the same subject.