We just kind of know these things from our memories. 
Although I have been trying to write down most of these things on the Thomas TrackMaster wikia, the Plarail article on Wikipedia (http://en.wikipedia.org/wiki/Plarail), and the Plarail article on the Japanese Wikipedia (http://translate.google.com.au/translate...rev=search) make for some good reading. For some reason, the Japanese for Plarail also gets translated as Tomy.
Although I have been trying to write down most of these things on the Thomas TrackMaster wikia, the Plarail article on Wikipedia (http://en.wikipedia.org/wiki/Plarail), and the Plarail article on the Japanese Wikipedia (http://translate.google.com.au/translate...rev=search) make for some good reading. For some reason, the Japanese for Plarail also gets translated as Tomy.