The brokenlinks directive is supplied by the brokenlinks plugin.

This directive generates a list of broken links on pages in the wiki. This is a useful way to find pages that still need to be written, or links that are written wrong.

The optional parameter "pages" can be a PageSpec specifying the pages to search for broken links, default is search them all.

Example:

[[!brokenlinks  pages="* and !recentchanges"]]