The tradition of wearing distinctive academic costumes originated in the medieval universities of Europe, where regulations governing gowns, hoods, and caps were enforced from the fourteenth century onward. In 1894 or 1895 representatives of Princeton, Yale, and New York University—advised by a manufacturer of academic dress—adopted the Intercollegiate Code of Academic Costume. In 1932 the American Council on Education appointed a committee to update that code for submission to the membership for approval. The ACE reviewed and modified the code again in 1959 and again in 1973 and 1987, making clear with each revision that the code represented guidelines rather than rules for member institutions.
The code provides detailed descriptions of all elements of academic dress. Essentially, however, American academic regalia indicates the highest degree earned by the wearer, the institution that conferred the degree, and the field of study in which the degree was earned. The gown tells the degree, and the academic hood tells the institution that awarded the degree and the discipline in which it was earned. The tassel on the hat worn with academic regalia signifies by being worn on the left side that the degree has been earned. Traditionally, students earning the baccalaureate degree enter the commencement ceremony with the tassels on the right and move them to the left following the conferring of the degrees.