When J.D. gives Dr. Cox the "Book of Rants" and Dr. Cox asks him where to look up any specific rant, J.D. replies with "you go to the glossary..." This statement is incorrect, because a glossary is where to look up the definitions of words used in the book. J.D. should have directed him to the index of the book.
Look closely; the penny that the Janitor claims to be the one that J.D. put in the door on his first day is stamped with the year 2006. J.D.'s first day was in 2001.
"Snow (Hey Oh)" by Red Hot Chili Peppers (Opening scene)
Original International Air Dates:
Australia: June 1, 2009 on Channel 7
Latin America: August 5, 2009 on Sony Entertainment Television (a.k.a. Canal Sony)
Sweden: December 9, 2009 on TV6