Jim I want to mention that sometimes people send cards and keys in a regular white paper envelope and these small pieces of plastic cut open the sides and fall out. I have paid big bucks postage for ebay cards thinking they would arrive in bubble wrap, but find only they have cut the ends of the small white paper envelope and have fallen into the postman's bag. Luckily I have gone to the PO and they had them in the lost and found box. Pat
PS--most of the people at my PO know what I collect, and if they do slide out of the package--they know they possibly belong to me.