Don't cross the post office

I learned something today.  There are strict rules about postcards.  I sent about 20 this weekend, and nine came back.  I had written my return address below the mailing address in the area which is for mailing addresses only (see the diagram below). I sent them back out in envelopes to avoid the hassle of going to the post office and trying to send them again.  On the back flap I wrote "I am using this envelope because I broke postal regulations."

Don't be like me.  Check the Postal Regulations before each mailing to be sure of success:

http://www.usps.com/all/mailingandshippingguidelines/welcome.htm

Standard 4" x 6" Postcard

 I added the Kilroy drawing, which is a favorite of mine.