Nicole emailed me with a great question: If you use the file by insert method for couponing, and you have a loose sheet (maybe someone gave it to you, or it fell out of your paper) is there a way to identify which insert it came from?
There are several coupon databases available on the internet. My personal favorite (because it's really the only one I've used), is at Hot Coupon World. Simply type the name of the product you are looking for into the database and it will list all the available coupons for that product. If you have a loose coupon, just match the value to the coupons in the database and you should be able to find the insert and date for that coupon.