2006 USSF Advice to Referees on the Laws of the Game
Law 15 — The Throw-In
15.1 LOCATION OF THROW-IN
Although the throw-in is to be taken "from the point where [the ball] crossed the touch line," this requirement is satisfied if the restart occurs within approximately one yard (one meter) of this location, farther upfield or downfield or back from the touch line. A throw-in taken beyond this limit is an infringement of Law 15.