DocBook is a document type derived from an ISO standard called XML (eXtensible Markup Language). (HTML, used to write World Wide Web pages, is also a markup language, and XML is similar in syntax.) All XML document types use the idea of tags to structure a document.
A tag always starts with a less-than character
<”) and ends with a
greater-than character (“
Most tags are used in pairs, with content enclosed between a start tag and an end tag.
For example, major sections of a document are always
enclosed between a
start tag and a
The term element refers to a pair of tags and everything in between them.
A start tag has the form
and the end tag has the form
is some name that describes what the tag does.
In some cases, you can specify optional
attributes that modify the characteristics
of the element. Each attribute has this form:
attribute's name and
is the attribute's value.
Here is an example of a start tag with attributes:
<itemizedlist spacing='compact' role='draft'>
An empty element is a
special element consisting of one tag. In this case,
the tag must have a forward slash (/) just before the
element describes the format of a table column in a
table (see Section 12, “Tables”).
You can add whitespace (spaces, tabs, or line breaks)
anywhere before or after an attribute, or before the