1.) a unit of <#stamp=stamps> produced for use in a traditional booklets (those with cardboard covers). Such booklet panes usually, but not always, have water activated gum. Panes in a traditional booklet usually (but not always) have six stamps. 2.) a unit of self-adhesive stamps sold by the post office as a complete <#booklet> that may be folded for the sake of convenience to form a <#convbooklet=convertible booklet>. 3.) a unit of stamps sold as a booklet through a <#vendmach=vending machine>.