one of a series of international stamp shows hosted once every decade in the U.S.; held in Washington, D.C. in 2006.

nickname for <#scott=Scott> 467, 485, and 505.  The <#tranroll=transfer roll> for a 5¢ <#stamp=stamp>, normally printed in blue, was mistakenly used on a <#plate> of 2¢ stamps printed in carmine, thus creating a color <#error> for the 5¢ stamp.

a private <#localpost=local post> established in New York City in 1841.  The first local stamp it issued (<#scott=Scott> 40L1) was the first adhesive stamp used in the United States.  This organization was purchased by the Post Office and re-organized as United States City Despatch Post.

nickname for the 1939 <#commem=commemorative> (<#scott=Scott> 858) marking the 50th anniversary of statehood for North and South Dakota, Montana and Washington.

island under U.S. administration from 1899 to 1902, and for which <#overprint=overprinted> U.S. <#stamp=stamps> were issued.