Parking: In order to park on campus as a student, you had to meet 3 criteria: be a senior, be 17, and have your parents' permission. My 17th birthday was a couple months into senior year, but the administration didn't get around to issuing parking stickers until
after my birthday... hehe
There was an office building down the street from the school. Juniors with driver's licenses parked there. It was even called the junior parking lot. That building's security force kept threatening to crack down, but nothing ever happened.
Off-campus privileges: Juniors and seniors were allowed off campus during free periods. My senior year, I had first period free => I slept in
Senior skip day: Actually, most Fridays from about April on turned into unofficial senior skip days. I was taking too many AP's, though
There was one official senior skip day, which "coincidentally" was the day yearbooks were distributed; you got your yearbook only if you attended your first-period class, otherwise you had to wait until after graduation. Did I mention I had first period free?
Pep rallies: These were mandatory. The day was shortened to create an hour at the end of the day for the pep rally. Since they were mandatory, school security patrolled the exits to make sure no students left.
Lots of people bailed on their 9th period classes to get out before security closed the gates. Unfortunately, I never could sneak out because I was on the track team.