private printer of <#poststamp=postage stamps>.  Their first stamp was the green denominated 29¢ Eagle and Shield of 1992, <#scott=Scott> 2596.

a <#duplex> <#handstamp>, common in the early 20th century, containing a numeral as a part of the <#cancel>.  The numeral indicates the annual compensation of the <#pm=postmaster>.  For example, a number 5 in the cancel means that for the year prior to the issuing of the handstamp, the postmaster’s annual compensation was between $400 and $499.

notation written on a <#cover> by the recipient.  Docketing sometimes helps establish the date of a cover.

<#revenue=revenue stamps> used to pay a federal tax on certain transactions that are documented on paper.  The stamps were attached to the documents.  They were first used in 1862 to help pay for the Civil War.  <#scott=Scott> numbers are prefixed with R.  Some documentary stamps have been <#overprint=overprinted> to serve other purposes.

mail that never leaves the mailstream of the United States, as opposed to <#internatl=International Mail>.