This document defines an abstract model for topic maps which makes explicit the implicit data models of ISO 13250 and XTM 1.0. It also defines a processing model for XTM 1.0 based on the data model.

The model is intended to present one possible approach to specifying a data and processing model for topic maps, believed by the author to be preferrable to other proposed approaches. It is hoped that this model may represent a first step on the way to a complete model for topic maps. Such a model would serve many purposes:

• Enable interoperability between topic map processors by defining precisely what topic map processors are required to do.
• Enable ancillary standards to be built on the topic map standard in a precise and controlled manner.
• Make it easier for newcomers to topic maps to understand what their abstract structure is and how they work.

This document is not complete; it is an early draft intended to show a possible approach to defining the topic map model. In particular, this document has no official standing whatsoever. It is, as stated above, just a draft proposal.