Options:

• SubWiki=0 (the default, no SubWiki)
• SubWiki=1 (the ParentPage becomes the root of a SubWiki, separate RecentChanges, Search, Index, ...) page changes are visible in the RecentChanges of the ParentWiki
• SubWiki=2 (unused)
• SubWiki=3 (like SubWiki=1, but changes are not visible in the parent RecentChanges)