DocBook 5: The Definitive Guide

Customization Layers

A RELAX NG grammar is a collection of patterns. These patterns can be stored in a single file or in a collection of files that import each other. Patterns can augment each other in a variety of ways. A complete grammar is the union of the specified patterns.

For convenience, the DocBook grammar is distributed in a single file.

RELAX NG Syntax

There are two standard syntaxes for RELAX NG, an XML syntax and a “compact” text syntax. The two forms have the same expressive power; it is possible to transform between them with no loss of information.

Many users find the relative terseness of the compact syntax makes it a convenient form for reading and writing RELAX NG. We will use compact syntax in our examples.

DocBook Schema Structure

The DocBook RELAX NG schema is highly modular, using named patterns extensively. Every element, attribute, attribute list, and enumeration has its own named pattern. In addition, there are named patterns for logical combinations of elements and attributes. These named patterns provide “hooks” into the schema that allow you to do a wide range of customization by simply redefining one or more of the named patterns.

The names of the patterns used in a RELAX NG grammar can be defined in any way the schema designer chooses. To make it easier to navigate, the DocBook RELAX NG grammar employs the following naming conventions:

db.*.attlist

Defines the list of attributes associated with an element. For example, db.emphasis.attlist is the pattern that ...