second. The first parameter can be either a page name, or some other
destination file, as registered by `will_render`.
+If the second parameter is `undef`, the URL will be valid from any page on the
+wiki, or from the CGI; if possible it'll be a path starting with `/`, but an
+absolute URL will be used if the wiki and the CGI are on different servers.
+
If the third parameter is passed and is true, an absolute url will be
constructed instead of the default relative url.
This is used to get the page creation time for a file from the RCS, by looking
it up in the history.
-It's ok if this is not implemented, and throws an error.
-
If the RCS cannot determine a ctime for the file, return 0.
#### `rcs_getmtime($)`
so `rcs_commit_staged` will complete it. It should return undef on _success_
and an error message on failure.
+This hook and `rcs_preprevert` are optional, if not implemented, no revert
+web interface will be available.
+
### PageSpec plugins
It's also possible to write plugins that add new functions to