Thread:Extension talk:ParserFunctions/ switch in MediaWiki:Pagetitle/reply

I looked over these pages:

Manual:FAQ Thread:Project:Support_desk/Is_it_possible_to_change_page_title%3F

and I think you may need to change your #switch to something like this:

Your mistake may have been not using or  to determine what page you're on. See Help:Magic words for more info about those. However, I'm not 100% sure that will work, since I haven't tried it. That would only work if MediaWiki treats MediaWiki:Pagetitle like a transcluded page, which I suspect it does.