All members of the University are required to wear academic dress with sub fusc clothing on a number of occasions.
This page explains what you need to wear when
You may be denied entry to formal University ceremonies and examinations if you are incorrectly dressed, or your interpretation of sub fusc clothing is deemed to be in appropriate.
Undergraduates: sub fusc clothing, Commoner's gown, mortarboard (or women may have a soft cap in place of mortarboard)
Graduates: sub fusc clothing and one of
Gowns, mortarboards, and soft caps may be bought at any Oxford tailor's shop, and may be available second-hand. You may also be able to buy them through the Oxford University Student Union.
Dress for undergraduates and graduates is as for Matriculation. However, an undergraduate who is entitled to wear a Scholar's gown may wear this instead of a Commoner's gown.
If you are taking a degree in person, you must wear the robes (gown, hood, cap) of that degree. At some Degree Days, you will begin the ceremony wearing the robes of your current status, and change into the robes of the degree you are taking. You will in advance of the ceremony be sent information on robe requirements and how to obtain robes.