If the university really is preventing you from deeming anything mandatory, the national offices of the Greek orgs need to step in. I'm guessing the athletic teams have practices they must attend - if so, the university has no leg to stand on with this "nothing is mandatory" jazz.
This.
Don't mess with elderly women who have donned the catsuits!
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~ *~"ADPi"~*~
♥Proud to be a Macon Magnolia ♥
"He who is not busy being born is busy dying." Bob Dylan