If you plan to travel outside of the United States and reenter the United States, please make sure you have a valid travel signature on your I-20. Schedule an appointment with International Student & Scholar Services to get a travel signature.
If you are planning to leave the United States and plan to reenter, please make sure to take all I-20's with you. If you leave the country, you may not be permitted back again without the correct documentation. Bring all I-20s, financial support documents, your I-94, and anything else verifying your legal status.
Talk to I.S.S.S. if you intend to leave the United States while you are waiting for your OPT authorization.