Base elements include the core DITA topic and map elements
that are the building blocks for other specializations as well as
several basic specializations that are not applicable to a specific
The base topic elements include elements that make up the
core building blocks of the DITA topic, such as topic, body, and related-links,
as well as elements like <p> and <ph> that are used in many
topic specializations. Some of these elements are also available inside
the <topicmeta> map element.
Metadata elements include information that is located within
the <topicmeta> element (in maps) or <prolog> element (in topics),
as well as indexing elements that can be placed in additional locations
within topic content.
Classification elements support managing metadata. Those
in the Subject Scheme map are used to define controlled values, and
to bind them to DITA attributes as enumerations. Those declared in
the classification domain are used in other maps to classify content
according to the scheme.
Several DITA elements exist either for architectural reasons
or for support of specialized markup yet to be designed. Although
there is little need to use these elements unless you are directed
to, some of them, such as <state>, can be
used if your content makes use of these semantic distinctions. For
example, a discussion of signals on a gate of an integrated logic
circuit might use the state element to represent either on or off
conditions of that gate.
A conditional processing profile (DITAVAL file) is used
to identify which values are to be used for conditional processing
during a particular output, build, or some other purpose. The profile
should have an extension of .ditaval.