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ok ive never seen this in my life, I was just listening to the ipod relaxing looking a NYCT pics and i came across this http://www.nycsubway.org/perl/show?2485 before you read the info at the bottom just take a moment to look at it lol. Yes it will make you scratch your head
Unfortunately it has been seen by many people already, especially if you had the that Subway Cars book.