From the panhellenic compact:
1. A woman who is or who has ever been an
initiated member of an existing NPC fraternity shall not be eligible for membership in another NPC fraternity.
4. A signed Preference Card or a Continuous Open Bidding Acceptance Card is binding. If the rushee receives a bid under the preference system, she is ineligible to be pledged to any other national fraternity on the same campus for one calendar year. If the rushee does not receive a bid under the preference system, she is eligible for continuous open bidding. If the rushee transfers to another campus during the year, she is eligible for pledging on that campus at the earliest possible opportunity.
6. A student who has had her pledge broken by a fraternity, or who has broken her pledge to a fraternity, may not be asked to join another fraternity on the campus for one calendar year from the date she was originally pledged. However, she may be repledged by the same fraternity chapter at any time within that calendar year.
7. When a pledge transfers to another campus, her pledge is broken, and she is eligible to pledge an NPC fraternity on that campus at the earliest opportunity.
8. Pledges of a chapter whose charter has been rescinded or relinquished shall be eligible to pledge another fraternity immediately following the official release of the pledges by the fraternity. Pledges of a colony which has been dissolved shall be eligible to pledge another fraternity immediately following the official release of the pledges by the fraternity.
I think that about covers it.
