DITA maps are documents that organize topics and other resources into structured collections of information. DITA maps specify hierarchy and the relationships among the topics; they also provide the context in which keys are defined and resolved. DITA maps should have .ditamap file extensions.
Maps draw on a rich set of existing best practices and standards for defining information models, such as hierarchical task analysis. They also support the definition of non-hierarchical relationships, such as matrices and groups, which provide a set of capabilities that has similarities to Resource Description Framework (RDF) and ISO topic maps.
DITA maps use <topicref> elements (or specializations of the <topicref> element) to reference DITA topics, DITA maps, and non-DITA resources, for example, HTML and TXT files. The <topicref> elements can be nested or grouped to create relationships between the referenced topics, maps, and non-DITA files; the <topicref> elements can be organized into hierarchies in order to represent a specific order of navigation or presentation.
DITA maps impose an architecture on a set of topics. Information architects can use DITA maps to specify what DITA topics are needed to support a given set of user goals and requirements; the sequential order of the topics; and the relationships that exist among those topics. Because DITA maps provide this context for topics, the topics themselves can be relatively context-free; they can be used and reused in multiple different contexts.
DITA maps often represent a single deliverable, for example, a specific Web site, a printed publication, or the online help for a product. DITA maps also can be subcomponents for a single deliverable, for example, a DITA map might contain the content for a chapter in a printed publication or the troubleshooting information for an online help system. The DITA specification provides specialized map types; book maps represent printed publications, subject scheme maps represent taxonomic or ontological classifications, and learning maps represent formal units of instruction and assessment. However, these map types are only a starter set of map types reflecting well-defined requirements.
DITA maps establish relationships through the nesting of <topicref> elements and the application of the @collection-type attribute. Relationship tables may also be used to associate topics with each other based on membership in the same row; for example, task topics can be associated with supporting concept and reference topics by placing each group in cells of the same row. During processing, these relationships can be rendered in different ways, although they typically result in lists of "Related topics" or "For more information" links. Like many aspects of DITA, the details about how such linking relationships are presented is determined by the DITA processor.
DITA maps also define keys and provide the context in which key references are resolved. A <topicref> element (or specialized <topicref> such as <keydef>) may be used to define a key which binds that key name to a specified resource.