"The rules adopt a new term "pattern day trader," which includes any
margin customer that day trades (buys then sells or sells short then buys the same security on the same day) four or more times in five business days, provided the number of day trades are more than six percent of the customer's total trading activity for that same five-day period."
A couple of more links/images that I found:


[This message has been edited by StupidisMe (edited 6/22/2009 1:29p).]