$rev: the new revision
$baseID: the revision ID this was based off, if any
+'OpenSearchUrls': Called when constructing the OpenSearch description XML.
+Hooks can alter or append to the array of URLs for search & suggestion formats.
+&$urls: array of associative arrays with Url element attributes
+
'OutputPageBeforeHTML': a page has been processed by the parser and
the resulting HTML is about to be displayed.
$parserOutput: the parserOutput (object) that corresponds to the page