DITA encourages the linking relationships to be stored outside the topic content. Links can be generated from topic hierarchies, relationship tables, and related-links section links.
The collection-type attribute of the topicref element defines the relationship between any nested topic references within a ditamap. Changing the collection type affects the way in which automatic links and topic previews are generated when the ditamap is processed to an output format.
The effect of the collection-type attribute on the output publication is well illustrated with examples of the results of the use of different types.
Topics are the building blocks of modular documents, and organising topics by semantic information types is one of the architectural features of DITA.
DITA map files are used for defining the topics of a publication, specifying the topic sequence, and controlling linking between topics.
Any topics referenced anywhere in the ditamap will be processed into the output publication.
In DITA, the sequence and hierarchy of the topics to be published are defined in the ditamap through nested topicref elements.
Relationship tables are used to store linking relationships between topics in a collection in the ditamap, rather than in individual topics. Linking relationships are defined in a table-like structure, with rows in the table determining which topics are linked to which.
The hierarchical relationship of topic references in the ditamap can be used to generate links from parent topics to child topics, from child topics to parent topics, and between child topics.
Links can be generated into output formats during publishing based on hierarchical and relationship table relationships in the ditamap. Regardless of the source, the links are merged during publishing.
The linking attribute of the topicref and relcell elements in the ditamap is used to specify the way in which links are generated during publishing.
Breadcrumb trails are navigation tools used in some online document formats, and can be automatically generated from DITA source.
Properties in ditamaps sometimes cascade from parent elements to child elements. Some values in ditamaps also override the equivalent values in referenced topics.
The technique of using embedded, or nested, ditamaps can make it easier to manage documents by separating complex collections of topics into a number of smaller, simpler collections.
Bookmaps are a specialisation of the base DITA map information type. Like ditamaps, bookmaps are containers for structure and context metadata, and do not contain any content. Bookmaps are used to describe page layout publishing outputs such as books, articles, manuals and research papers. They contain information structures that are specific to linear publications, such as tables of figures, title pages, chapters, sections and parts.
Cross-references are a means of binding individual topics into a coherent and navigable document.
Moving from style-based authoring to a structured authoring methodology such as DITA requires a radically different approach to writing.
