F-2 Visa Application form question regarding SEVIS Number


I am currently in process of taking a F-2 VISA Appointment Date for my wife. While filling out the Appointment details on http://www.ustraveldocs.com/. I came across a personal data tab which required following information:-

STUDENT AND EXCHANGE VISITOR PROGRAM DETAILSSEVIS Number :-University Name :-University Zip Code :-Principle Applicants Name:-Principle Applicants Visa Status:-

My Question is whose SEVIS number needs to be added in field. Whether it should be principle applicants sevis number or the F2 visa applicants sevis number.So to put it in another way whether it should be F-1 's SEVIS number or F-2’s SEVIS Number.

Attaching the snapshot as well.

Did you get an answer to this?