Requirement?!
I haven't heard of one other than the "here's a rope, here's how you're supposed to climb it" I got on basic (we weren't allowed to climb it at the time because a candidate had fallen and broken his neck the year earlier). I was told though that it's recommended for candidates prior to our selection. If i'm nit picking with this then feel free to call me on it, i just wanted to cover all bases before I set this jobby up.