&$sortkey: Sortkey to use.
'GetDifferenceEngine': Called when getting a new difference engine interface
-object Return false for valid object in $differenceEngine or true for the
-default difference engine.
+object. Can be used to decorate or replace the default difference engine.
$context: IContextSource context to be used for diff
$old: Revision ID to show and diff with
$new: Either a revision ID or one of the strings 'cur', 'prev' or 'next'
$refreshCache: If set, refreshes the diff cache
$unhide: If set, allow viewing deleted revs
-&$differenceEngine: output parameter, difference engine object to be used for
- diff
+&$differenceEngine: The difference engine object to be used for the diff
'GetDoubleUnderscoreIDs': Modify the list of behavior switch (double
underscore) magic words. Called by MagicWord.