The stylesheets support XLink extended links. Extended links make it possible to have one-to-many links. That is, a single link such as DocBook▶ [DocBook.org, DocBook on Wikipedia] may point to more than one target. Three styles are supported:

inline

Renders a link to each target inline after the originating link.

javascript

Uses JavaScript to render the links in a drop-down menu.

document

The preceding XLink styles apply to the entire document, you cannot specify inline presentation in some cases and JavaScript presentation in others. However, if you specify “document” as the value for $xlink-style, then a db processing instruction in the document’s top-level info element can be used to control the presentation. Specify the style in the xlink-style pseudo-attribute.

If the document style is selected and no processing instruction specifying a style exists, the $xlink-style-default style will be selected.