"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. In the United States this is called the "Congressional frank" which can only be used for "Official Business" mail.
According to Wikipedia, "In the United States, the franking privilege predates the establishment of the republic itself, as the Continental Congress bestowed it on its members in 1775. The First United States Congress enacted a franking law in 1789 during its very first session. Congress members would spend much time "inscribing their names on the upper right-hand corner of official letters and packages" until the 1860s for the purpose of sending out postage free mail.
"Yet, on January 31, 1873, the Senate abolished "the congressional franking privilege after rejecting a House-passed provision that would have provided special stamps for the free mailing of printed Senate and House documents." Within two years, however, Congress began to make exceptions to this ban, including free mailing of the Congressional Record, seeds, and agricultural reports. Finally, in 1891, noting that its members were the only government officials required to pay postage, Congress restored full franking privileges. Since then, the franking of congressional mail has been subject to ongoing review and regulation."
The site goes on to say, "The phrase franking is derived from the Latin word 'francus' meaning free. Another use of that term is speaking 'frankly'i.e. 'freely'. Because Benjamin Franklin was an early United States Postmaster General, satirist Richard Armour referred to free congressional mailings as the 'Franklin privilege'.
It is interesting to note that the President of the United States does not have personal franking privileges but the vice president, who is also President of the Senate, does.
Shown above, a U.S. Congressional franked mailing.
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