upperclassman quota

[Mevara]

So I know a few campuses do this and would just like to know more about this for my benefit. They didn't do this where I went to school.

First of why do they do it? Is it because at those campuses if you were an upperclassman you would get cut heavily? or to spread out the upperclassmen evenly?

What is considered upperclassman? Sophomores and above, or just juniors?

How does work logistically? When you make your invitation list for each day do they have two list, one for underclassman and one for upperclassman? Or is this only for quota?

Thanks!