A data module represents the smallest self-contained information unit within a technical publication. Exactly what constitutes a data module is for the author to decide and it will depend on the size of the publication and how much content is suitable for reuse. A data module could represent an entire document, if it is only a few pages and the content is only suitable for re-use in its entirety; or it could represent a chapter, section, sub-section, paragraph or something as small as a list, if that list could be re-used in multiple documents. The data module consist of a single XML file with a root element <dmodule> and two main sections: the identification and status section <identAndStatusSection> and the content section.

                    <dmodule>
                        <identAndStatusSection>
                            <dmAddress>
                            ...
                            </dmAddress>
                            <dmStatus>
                            ...
                            </dmStatus>
                        </identAndStatusSection>
                        <content>
                        ...
                        </content>
                    </dmodule>
                

The identification and status section contains the metadata and management information and is further broken down into the data module address element <dmAddress> which contains identification information such as numbering, revision and title, and the data module status element <dmStatus> which contains information such as providence, security classification and applicable business rules.

The content section of the data module contains the text and illustrations displayed to the user. The structure of this section varies depending on the type of publication and the data module schema being used. The available schemas (version 4.1) are shown in the following table: