* `presence` if set to true, only the presence of a matching page triggers
the dependency.
-* `links` if set to true, any change in the text of links on a matching page
- triggers the dependency
+* `links` if set to true, any change to links on a matching page
+ triggers the dependency. This includes when a link is added, removed,
+ or changes what it points to due to other changes. It does not include
+ the addition or removal of a duplicate link.
#### `pagespec_match($$;@)`
-Passed a page name, and [[ikiwiki/PageSpec]], returns true if the
+Passed a page name, and [[ikiwiki/PageSpec]], returns a true value if the
[[ikiwiki/PageSpec]] matches the page.
+Note that the return value is overloaded. If stringified, it will be a
+message indicating why the PageSpec succeeded, or failed, to match the
+page.
+
Additional named parameters can be passed, to further limit the match.
The most often used is "location", which specifies the location the
PageSpec should match against. If not passed, relative PageSpecs will match
attempted at all, for any page, it can instead return an
IkiWiki::ErrorReason object explaining why.
+When constructing these objects, you should also include a list of any
+pages whose contents or other metadata influenced the result of the match.
+For example, "backlink(foo)" is influenced by the contents of page foo;
+"link(foo)" and "title(bar)" are influenced by the contents of any
+page they match; "created_before(foo)" is influenced by the metadata of
+foo; while "glob(*)" is not influenced by the contents of any page.
+
### Setup plugins
The ikiwiki setup file is loaded using a pluggable mechanism. If you look