[justabeachbrat]

My high school didn't have sororities, but did have girls clubs that ruled the school. Oddly, they were run by Y. There were several of these clubs, and each group had a sweater, a section of the lunch area carved out that one did not cross unless being a member, and a pecking order, from the best to the not-so-hot groups. There was a form of rush, with membership gained only by being voted in and what would be considered hazing. I was a "legacy" of a group my older sister was in before she graduated. Being in my "blimp" stage at the time, I was told by the members that this was the only reason I was allowed to join. I quit, leaving the dear girls.
After high school, I went to junior college, then tranferred to the nearby state college which had an active Greek system. Once on campus, it felt as if my high school had followed me there. Girls from those "in" high school clubs were ruling the top houses, and I avoided those houses, it was too weird.
The high school seemed to have no control over these groups. My mother, who can be a crusader, was very upset about the hold the clubs had on the high school and tried through the board of education to get them tossed off campus. This was in my sister's freshman year. My sister had her back off when word went around school that my sister would be a social outcast if my mother continued to rock the boat. Much to my mother's dismay, my sister joined a club the following year. It was basically understood that if you wanted to date the cute guys--jocks, student leaders, etc., you gained membership into one of these clubs, and the hotter the girls, the better.
I have no idea if the school still allows the clubs, I hope not.