well the whole thing was a sit/com, and the nuns seemed to have a life quite unlike any nuns i knew, and i had several cousins who were members of different regilious orders, so i got see/learn about rules and religious orders (as well as learning a thing or two from the ursulines)
there is an order of nuns, (dedicated to teaching and healing the sick ) that do wear elaberate folded head dresses..similar enough to the ones on the show.
the style of head dress that was common enough at the time the order was founded (just as nuns mother theresa 'order' wear sari's)-- nuns habits look strange now, because the reflect styles of the past..
most RC priest are just priests--not members of a specific 'order' they wear a collar, and cassock (sometimes--manytimes they just wear a collar).
there are also 'orders' of brothers(monks) that also include priests--and there are orders of just priests, --like the jesuits,-- an order that has as part of its function, a dispensation from wearing any sort of habit, or special clothing..jesuits are part of the papal equivelent of the CIA--and are undercover priests, and wear 'street clothing'
many ordersof monks, ie, fransicans, (mostly monks, but may also be priests) also wear anchronistic clothes/habits.
franciscans wear coarse *brown wool robes, (and coarse wool under robes) they are tied with rope (not leather) and they wear simple leather sandles (not shoes) -- and special permission has to be granted to them to wear socks even in the cold weather (like now in NY, temp is close to freezing, and is expected to be well below freezing mark tomorrow).
*actually the franciscans wear coarse wool robes make from native wool. in England, they tended to wear grey wool (unbleached simple wool) and were called the 'grey friars'.
many orders of monks are 'cloistered' (as are a percentage of nuns)--they are less often seen.
