I agree with the two previous posts, and I believe that a lot of good info can be learned from there.
The only thing I do not agree completely is the part about two polychordal notations, for I am positive that they are two separate things.
The chord notated with the slash is called Slash Chord or more properly Hybrid Chord.
The chord notated as a fraction refers to the actual Polychord type.
Other than that everything is of useful information.