Alphabetti Spaghetti

Here's a couple of alphabet related questions for you... (Bertie already knows one of these, so she can't reply.)

What have the letters I, K, L, V, W, X, Y and Z all got in common?

And secondly, a really nasty one.

What have the letters C, K, O, P, S, U, V, W, X and Z all got in common?