Tap Test —When a insert showing through the window is moved to any of its limits inside the envelope, the entire barcode must remain within the barcode clear zone, and a clear space must be maintained that is at least 1/8 inch between the barcode and the left and right edges of the window, at least 1/25 inch between the barcode and the top edge of the window, and at least 3/16 inch between the barcode and the bottom edge of the mailpiece.

 

Top Cap —Material that forms a flat, level surface horizontal to the base of a pallet that is used to protect the integrity of the mail under the top cap while also supporting a loaded pallet above. A top cap must be secured to a pallet of mail with either stretchwrap or at least two crossed straps or bands.

 

Tray —A container used in postal facilities to hold letters and First-Class Mail flats. It is used as a basic unit of mail quantity for purposes of preparing mail to qualify for discounted postage. Also see full flat tray, full letter tray, less-than-full tray, and overflow tray.