Modified Pitch - what does modified mean exactly?

[raresco]

I'm in a modified pitch league and most of us have been of the understanding that modified pitch meant that you can pitch it as fast as you can, as long as your arm does not go more than parallel to the ground. However - last night the other team had a fireballer who was bringing his arm all the way back so he was nearly pointing at the sky. Can someone please give me some clarification as to the ASA ruling on this? Thanks!