Polarising filters, two types, Linear and Circular, whilst not particular about whether they are on a film or a digital camera, they can effect AF.
A linear polariser will work fine on a manual focus camera, since there are not too many manual focus digital camera's (its a choice not a condition), they are generally associated with film, but can mess with af.
So if you are offered a polariser as part of a film "kit", and you intend to use it on an af camera, make sure its a circular polariser.