Well aware of the rich and intricate traditions associated with this wonderful institution I have nonetheless managed to get to 4th year without really understanding the proper wearing of gowns.
I think the rules are if you're an undergraduate in arts or science then you wear a "Scarlet red cloth gown with open sleeves half the length of the gown and burgundy velvet collar". And if you're an undergrad studying divinity then you wear a "Black stuff gown of knee length with short open sleeves and with a violet Cross of St Andrew in the left facing."
But if you were doing a joint honours degree and studied an arts subject + a divinity, or a science + a divinity, what are you allowed to wear?
Then you can, once graduated, wear a hood with a design relevant to what you graduated with. e.g. Master of Arts (M.A.): Black silk with cherry silk lining, Bachelor of Science (B.Sc): Purple-lilac silk or cloth bordered with white fur. Where would you acquire one of these and for how much? Does anyone bother? Do you slip it on the moment you finally get your degree at graduation?