Overview
The academic dress found in most universities in the British Commonwealth and the United States is derived from that of the universities of Oxford and Cambridge, which was a development of academic and clerical dress common throughout the medieval universities of Europe.
Formal or sober clothing is typically worn beneath the gown so, for example, men would often wear a dark suit with a white shirt and tie, or clerical clothing, military or civil uniform, or national dress, and women would wear equivalent attire. Some older universities, particularly Oxford and Cambridge, have a prescribed set of dress (known as subfusc) to be worn under the gown. Though some universities are relaxed about what people wear under their gowns, it is nevertheless considered bad form to be in casual wear or the like during graduation, and a number of universities may bar finishing students from joining the procession or the ceremony itself if not appropriately dressed (though this sometimes refers only to requiring the proper wear of academic dress and not what is worn beneath it, if unseen).
Read more about this topic: Academic Dress