All topics have the same basic structure, regardless of
topic type: title, description or abstract, prolog, body,
related links, and nested topics.
All DITA topics must have an XML identifier (the @id
attribute) and a title. The basic topic structure consists of the
following parts, some of which are optional:
- Topic element
- The topic element holds the required @id attribute and contains all other elements.
- The title contains the subject of the topic.
- Alternate titles
- Titles specifically for use in navigation or search. When not
provided, the base title is used for all contexts.
- Short description or abstract
- A short description of the topic or a longer abstract with an
embedded short description. The short description may
be used both in topic content (as the first
paragraph), in generated summaries that include the topic, and in
links to the topic. Alternatively, the abstract
lets you create more complex introductory
content and uses an embedded short description element to
define the part of the abstract that is suitable for
summaries and link previews.
short descriptions aren't required, they can make a dramatic
difference to the usability of an information set
and should generally be provided for all topics.
- The prolog is the container for topic metadata,
such as change history, audience, product,
and so on.
- The topic body contains the topic content:
paragraphs, lists, sections, and other content
that the information type permits.
- Related links
- Related links connect to other topics. When
an author creates a link as part of a topic,
the topic becomes dependent on the other topic
being available. To reduce dependencies between topics and thereby
increase the reusability of each topic, authors
may use DITA maps to define and manage links
between topics, instead of embedding links directly in each
- Nested topics
- Topics can be defined inside other topics. However, nesting requires
special care because it can result in complex documents that are less
usable and less reusable. Nesting may be appropriate for information
that is first converted from desktop publishing or word processing
files or for topics that are unusable independent from their parent
or sibling topics.
- The rules for topic nesting
can be configured in a document-type shells. For example, the standard
DITA configuration for concept topics only allows nested concept topics.
However, local configuration of the concept topic type could allow
other topic types to nest or disallow topic nesting entirely. In addition,
the @chunk attribute enables topics to be equally re-usable regardless
of whether they are separate or nested. The standard DITA configuration
for ditabase document-type documents allows unrestricted topic nesting
and may be used for holding sets of otherwise unrelated topics that
hold re-usable content. It may also be used to convert DITA topics
from non-DITA legacy source without first determining how individual
topics should be organized into separate XML documents.