As a graduate, you will need to wear full academic dress appropriate for your degree or diploma, at your graduation ceremony. Full academic dress comprises a gown, bonnet/trencher cap, and hood or stole.
You can make, buy or hire academic dress, although the most popular choice is to hire it.
Wearing academic dress has its own rules.
One of the most important is that the tassel on your trencher should remain on the right side until you have shaken hands with the Chancellor. Once the photograph of you and the Chancellor is complete, you can switch the tassel to the left side to signify that you are a graduate.
Men should wear their trencher only when standing. Women wear theirs both standing and seated. If you wear a head-covering for religious or other specific reasons, you are not required to wear a trencher.