This field controls whether or not the number of items specified by Y must be met in order for those items to be discounted. For example:<br><br>
<i>Buy 3 get 2 for 30% off</i><br><br>
If the customer bought 4 items, and "Enforce Y" was not checked, the fourth item in this example would be 20% off. If "Enforce Y" was checked, then they would need to add one more unit (5 in total) to get the 20% off.