reference.
* `%pagesources` contains the name of the source file for a page.
+Also, the %IkiWiki::version variable contains the version number for the
+ikiwiki program.
+
### Library functions
#### `hook(@)`
Hook into ikiwiki's processing. See the discussion of hooks above.
+Note that in addition to the named parameters described above, a parameter
+named no_override is supported, If it's set to a true value, then this hook
+will not override any existing hook with the same id. This is useful if
+the id can be controled by the user.
+
#### `debug($)`
Logs a debugging message. These are supressed unless verbose mode is turned