Patent US 5,285,958

A two-way envelope includes front and back panels having a portion removable to open the two-way envelope with the other portion forming a reply envelope having an end closure flap for closing the reply envelope. The two-way envelope is preprinted with a reply address, a bar code corresponding to the reply address and an identification code indicating the presence of the bar code. After the two-way envelope is opened and the reply envelope closed, the reply envelope includes the reply address, bar code and identification code but not the outgoing address of the two-way envelope.