This is standard countdown leader, counting down 8 to 3 and then with one frame of 2, at which point there is a single frame beep on the sound track. It is used at the beginning of a film for the lab to line up sound (using the beep) and later for the projectionist to know when to turn on the lamp and hopefully not miss the opening of the film. A common mistake is to count the footage from the 2, but actually frame zero is the one right before the first 8, a single frame with the words “Picture Start.” Academy Leader is sometimes also known as S.M.P.T.E. leader.
Glossary of Flim Terms - http://homepage.newschool.edu/~schlemoj/film_courses/glossary_of_film_terms/
reprinted with permission