I do not think that PH stands for Phillips Head, but i do NOT know that for certain. My reasoning is that I have a security but set which has CR-VPH0, 1, 2 and 3, but ALSO has CR-VPZ0, 1, 2, 3. They are ALL Philips Head, but the difference is the ones with "H" have what looks like maybe a flattened point. Also, the "Z" ones have a slight "raised ridge" between the any two of the four blades of the bit. It is not much of a raised edge, but it is definitely there. (See pic for reference. Sorry if it is not very clear but Iam definitely NOT a photographer). Again, I am not certain about the label definition, but I am certain there is a difference.
[image|3537887]