The "non-announced" rush is basically = COB. The good part is you do have a better chance of getting a bid despite your junior status, the bad part is you won't have all the sororities to choose from. If you know which ones do COB and you like them, I would say go for it.
Iowa Hawkeye was a founder of her DZ chapter - maybe she will be able to fill you in on how to get involved if that is what you would like to pursue.
Either way, GOOD LUCK!!
