I recently needed to visit Wimbledon and decided to use the tram to Croydon in one direction for a bit of variety. I was struck by how poor the instructions for touching in and out were, especially when interchanging between train or tube and tram. It seems like they have forgotten to update the instructions since Oyster started being accepted on National Rail from Wimbledon. The explanation alongside the pink route validators also fail to specify that they are not appropriate when interchanging with a tram.
In view of this I have set up two new pages, one covering usage of Oyster on Trams and Buses and another explaining the unusual arrangements required at Wimbledon.