Specialized cross references

Specialized cross references
	Chapter 14. Cross references

DocBook can create some cross references automatically without reference to an id, if you set up your documents properly and turn on the right parameters.

You can automatically form links from your text to a glossary entry if you set the glossary.auto.link parameter to 1. See the section “Linking to a glossary entry” for more information.
When you create a back-of-the-book index, the index entries becomes links from the index to locations in the document. See Chapter 18, Indexes for more information.
When you create footnotes, a link is automatically formed from the footnote mark in the text to the footnote at the bottom of the page. In HTML output, the reverse link is also created. That is, the mark in the footnote links back to the matching mark in the text. See Chapter 15, Footnotes for more details.

DocBook also permits some elements to have a linkend-like attribute to form a cross reference to an id on another element.

Callouts

You can form links between a callout marker and its associated callout text. A co callout marker can take a linkends attribute (note the plural) to point to the callout element that contains its text. A callout elements can take an arearefs (not linkend) attribute to point back to its co element. See the section “Callouts” for more information.

If you are using area elements in programlistingco to attach callout markers to imported text, then you can put a linkends (note the plural) attribute on each area element. See the section “Callouts on imported text” for more information.

Callout reference

When doing callouts, sometimes more than one place in your example needs to point to the same callout description. To make sure they have the same callout bug number, use a coref element instead of another co element. See the section “Callouts” for more information.

Synopses: If you are using a cmdsynopsis, you can break out parts of a complex command synopsis using synopfragment. You can insert a synopfragmentref with a linkend attribute to point to a synopfragment. See the reference page for synopfragment in DocBook: The Definitive Guide for an example.
Footnote reference: Sometimes you need to make more than one reference to the same footnote. For example, you might have two places in your text where the explanation in a footnote is appropriate. Rather than create two identical footnote elements, one of them can be a footnoteref element. That is an empty element with a linkend attribute that points to the id you put in the footnote element.
Glossary reference: You can link from your text into a glossary. An inline glossterm in a paragraph can have a linkend attribute that points to the id of a glossentry in a glossary. See the section “Linking to a glossary entry” for more information.


Customizing cross references		Chapter 15. Footnotes