Laudian Statutes (1636) on academic dress (prescribed source)
Title XIV, ch. 3. The Academical Dresses suited to each Degree and Faculty.
 It is enacted, that all under-graduates, who are fellows, probationers, scholars, chaplains, clerks or choristers of any college, and in a word all the foundationers of every college, and the students of Christ-Church, shall, whenever they walk out in public within the University, go in loose-sleeved gowns and square caps.  All fellow-commoners, commoners, batellers, and servitors, and in a word all persons who are not of the foundation of any college, are to go clad in long gowns and round caps, whenever they walk abroad within the University.
All graduates are to wear gowns adapted to their degree and faculty, and scarfs also, and square caps or round ones (that is to say the jurists and physicians), particularly at the sermons, ordinary lectures, and public disputations.
But at the solemn sermons, and on all Sundays during term, they must attend the sermons in the forenoon at the church of St. Mary the Virgin, and at Christ-Church, and during Lent and on Easter-Sunday, in the afternoon at St. Peter's in the East, with their capes and hoods of silk or miniver exposed.
The preachers, in like manner, shall go to church in the habit befitting their degree (according to the time, as it may fall within or out of term), and deliver their sermons in it, under a penalty of six shillings and eight pence.
The public readers and professors, too, at their ordinary lectures shall go to the schools dressed in gowns suitable to their degree or faculty, and in the scarf and cap, and lecture, and return again from the schools in the same habit. But during the solemn lectures at Vesperies, they shall go to the schools, and lecture, and withdraw in caps, capes, and hoods, conformable to their degree and faculty.
But whenever they go to congregations, convocations, public prayers, and sermons to the clergy, they shall all wear, in addition to the gowns, capes also, either close or open, and the hoods adapted to their degrees.
All the doctors shall attend the sermons during Sundays in term, in the forenoon at the Church of St Mary the Virgin, and during Lent and on Easter Sunday, in the afternoon at the Church of St. Peter in the East, dressed in the cape and scarlet hood.
But if any person shall be found offending in the above  particulars, if he is not a graduate, he shall be punished at the discretion of the Vice-Chancellor (with personal chastisement, if it agrees with his years); if a graduate, for the first offence by a fine of twenty pence, for the second, by one of three shillings and four pence, and for the third, by one of five shillings, for the fourth, by one of six shillings and eight pence, and so on for every offence. But if any one goes to Congregation or Convocation without his proper dress, he shall, in addition to the fine above mentioned, be deprived of all power of voting on that occasion. Not only the Vice-Chancellor, but the proctors too are to have the power of exacting the above fines for the use of the University. The proctors too are to be liable to similar punishments, if they are negligent in inflicting them.
But in order that no one may allege ignorance on account of the use of the dress suitable to the degree having been for a long while discontinued; or through the lust of change should attempt a departure from the ancient fashions and introduce novel dresses, it is enacted that the heads of colleges and halls shall determine at their weekly meeting, after making diligent inquiry concerning the gown, cape (whether close or open), hood, scarf, and cap suitable to each degree and faculty, particularly to those of the physicians and jurists. And, according as they agree, they shall take care that a pattern of each (of any cheap material) shall be got up, and deposited with the name affixed in a press or chest appointed for the purpose, in order that a model of every dress may be there found, in case at any time a question should arise in respect to these particulars. But if any person should attempt any innovation in the form of the dress appointed, he shall be punished at the Vice-Chancellor's discretion; and the tailors also shall be forbidden to depart even a nail's breadth from the received form or fashion of the dress suitable to each degree, under a penalty to be inflicted at the discretion of the Vice-Chancellor.
Source: Oxford University Statutes, translated by G. R. M. Ward, Volume 1: Containing the Caroline Code, or Laudian Statues, promulgated A.D. 1636 (London, 1845), pp. 152-4.