Individuals on an F visa who intend to travel outside the United States and return, must have written permission from a Wilson College DSO. The DSO will sign page 2 of the I-20 indicating that you are in good status and registered fulltime for the upcoming semester, if applicable. You also must be maintaining good status in the past. Students need to schedule an appointment in advance if a signature is needed. A travel signature is valid for 12 months or until the end of the academic program. The signature for students on post-completion OPT is valid for only 6 months.