How to change text on a back button

Question

By default the back button uses as a text on it a title of a viewcontroller. Can I change text on the back button without changing a title of a view controller? I need this

Answer 1

And in MonoTouch the following works (in ViewDidLoad of the parent controller):

NavigationItem.BackBarButtonItem = new UIBarButtonItem( "Back", UIBarButtonItemStyle.Plain, null);