Qualifications for the guard at the tomb of the unknown soldier?

Guarding the tomb of the unknown soldier is a very important job; that is why there is very stern qualifications for a guard to the tomb. One for example is that the person must be between 5'10" and 6'4" and Physiclly fit. Another is that before a person is even eligable to be one of the guards for this important tomb they must memorize seven pages of Arlington National Cemetery and then be able to recite it, and they must be a volunteer from the 3rd Infantry.