This is for the Settings App. It works in iOS 5, not sure about older versions. It links into parts of the Settings App.

Application homepage:
iTunes link:
HTML Link example: prefs:
Native application URL string example: prefs:
Extended example: general settings: @"prefs:root=General"network settings: @"prefs:root=General&path=Network"twitter settings: :@"prefs:root=TWITTER"There are more, but I you have to look around in Apple's code to find them.
Tags: settings, preferences, prefs, settings app

I found out about this from mpstx's post here: