[aephi alum]

I also joined my sorority via informal rush. I found it a LOT more laid-back and relaxed than formal rush, although it serves the same purpose - gives potential new members (PNMs) a chance to meet the sisters and find out more about the sorority, while giving the sorority a chance to meet PNMs and choose the ones they'd like to invite to join.

Whether informal rush parties are openly advertised depends on how many bids the sorority is able to extend. If they can only extend one or two bids, they probably won't advertise their parties - they'll just invite 4 or 5 women they already know well, and that's it. If they can extend 15 or 20 bids, then they'll advertise - and if you've already let them know you're interested, they'll give you a call.

You should also note that you're ineligible to participate in informal rush if you haven't already had the chance to participate in formal rush - the idea being that you should at least have had the opportunity to meet all the sororities via formal rush first. So if your school holds formal rush in January, and you're a freshman and it's November, you have to wait. However, if you're a sophomore, junior, or senior (even if you're a transfer, and even if you've never been through formal rush) you can participate in informal rush.