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 <boolean> and <state>, can be used if your content
makes use of these semantic distinctions. A discussion of signals on a gate
of an integrated logic circuit, for example, might use the state element to
represent either on or off conditions of that gate.
The <boolean> element is used to express
one of two opposite values, such as yes or no, on or off, true or false, high
or low, and so forth. The element itself is empty; the value of the element
is stored in its state attribute, and
the semantic associated with the value is typically in a specialized name
derived from this element. If you need more than two values (for example,
"yes," "no" and "don't care") use the <state>
element instead. This element is primarily for specialization, where
it can be used to require a logical true or false designation in a particular
part of the document.
The <itemgroup> element is reserved for use
in specializations of DITA. As a container element, it can be used to sub-divide
or organize elements that occur inside a list item, definition, or parameter
The <no-topic-nesting> element is a placeholder
in the DITA architecture. It is not actually used by the default DITA document
types; it is for use only when creating a validly customized document type
where the information designer wants to eliminate the ability to nest topics.
Not intended for use by authors, and has no associated output processing.
A <required-cleanup> element is used as a
placeholder for migrated elements that cannot be appropriately tagged without
manual intervention. As the element name implies, the intent for authors is
to clean up the contained material and eventually get rid of the <required-cleanup>
element. Authors should not insert this element into documents.
The <state> element specifies a name/value
pair whenever it is necessary to represent a named state that has a variable
value. The element is primarily intended for use in specializations to represent
specific states (like logic circuit states, chemical reaction states, airplane
instrumentation states, and so forth).
The <term> element identifies words that
may have or require extended definitions or explanations. In future development
of DITA, for example, terms might provide associative linking to matching
OASIS DITA Language Specification v1.0 -- 09 May 2005
Copyright (c) OASIS Open 2005. All Rights Reserved.