<P> "Postage" franking is the physical application and presence of postage stamps, or any other markings recognized and accepted by the postal system or systems providing service, which indicate the payment of sufficient fees for the class of service which the item of mail is to be or had been afforded . Prior to the introduction to the world's first postage stamps in Britain in 1840 ("Penny Black") and 1841 ("Penny Red"), pre-paid franking was applied exclusively by a manuscript or handstamped "Paid" marking and the amount of the fee collected . The first US postage stamp was the red brown Five cent Franklin (SC - 1) issued in 1847 . </P> <P> In addition to stamps, postage franking can be in the form of printed or stamped impressions made in an authorized format and applied directly by a franking machine, postage meter, computer generated franking labels or other similar methods ("Postage Evidencing Systems"), any form of preprinted "postage paid" notice authorized by a postal service permit ("Indicia"), or any other marking method accepted by the postal service and specified by its regulations, as proof of the prepayment of the appropriate fees . Postal franking also includes "Postage Due" stamps or markings affixed by a postal service which designate any amount of insufficient or omitted postage fees to be collected on delivery . </P> <P> "Privilege" franking is a personally pen - signed or printed facsimile signature of a person with a "franking privilege" such as certain government officials (especially legislators) and others designated by law or Postal Regulations . This allows the letter or other parcel to be sent without the application of a postage stamp . In the United States this is called the "Congressional frank" which can only be used for "Official Business" mail . </P> <P> In addition to this type of franking privilege, from time to time (especially during wartimes) governments and / or postal administrations also authorize active duty service members and other designated individuals to send mails for free by writing "Free" or "Soldier's Mail" (or equivalent) on the item of mail in lieu of paid postal franking, or by using appropriate free franked postal stationery . In the United States, unless otherwise designated, such mails are serviced by both the military and civil postal systems that accept them as First Class letter mail . </P>

Congress members receive free postage. what is this called