1. 
   precancel
   precancel To cancel the postage stamp on an envelope before mailing it.
   Found op http://www.wordinfo.info/words/index/info/view_unit/1744/2
   
   
2. 
   Precancel
   A precanceled stamp, or precancel for short, is a postage stamp that has been cancelled before being affixed to mail. Precancels are typically used by mass mailers, who can save a postal system time and effort by prearranging to use the precancels, and delivering the stamped mail ready for sorting....
   Found op http://en.wikipedia.org/wiki/Precancel
   
   

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