Handstamp - a stamp or overprint which has been applied to paper singly and without mechanical means; a hand-held apparatus for printing that is struck on an ink pad and then pressed on paper. The die may be of metal, rubber, or wood.
Handwritten plate number - handwritten numbers found where a die is not used
Harrow perforation - perforation generally used for small souvenir sheets in which the entire sheet is perforated in one operation
Highway Post Office Service - a mail distribution network. To compensate rural communities for the loss of Railway Mail Service, the Post Office Department inaugurated Highway Post Office (HPO) Service on February 10, 1941. President Franklin D. Roosevelt had signed a measure creating the Highway Post Office Service on July 11, 1940. The inaugural route ran between Washington, D.C., and Harrisonburg, Virginia. The expansion of the Highway Post Office Service was postponed during World War II. A second route was established in 1946. This new service, like railway service, was to be a mail distribution network comprised of rapid pick-up, sorting, and dispatch to key points en route between two principal terminal cities. Mail processed on HPO vehicles was transferred along the route to connecting Star Routes, mail trains, and to various rural post offices. Highway mail routes generally served an average of twenty-five post offices directly and many others indirectly through Star Route and railway mail connections. Highway Post Office routes were organized on round trips which averaged 150 miles each way. There were very good reasons for this: 1) the bus generally held enough gas for about one 150 mile trip, and fuel stops wasted time; 2) service garages would have to be set up at both terminal cities, doubling the cost. For roughly the next decade, as railway mail service shrank, highway mail service grew. From 1960 to 1963 HPO service was replacing an average of 20 trains a month. The service essentially became obsolete when the Post Office Department decided to reorganize its mail handling/distribution system by adopting the sectional center concept (see ZIP Code). On June 30, 1974, 33 years after the first experimental trip, the last Highway Post Office made its final run over the Cincinnati-Cleveland (Ohio) route. Ironically, Railway Mail Service outlasted Highway Post Office Service by three years.
Hotel stamp - a local stamp issued by a remotely located hotel to pay for delivery of guests' mail to the nearest post office. Some hotels had their own post offices.
HPO - an abbreviation of the Highway Post Office Service which operated between 1941 and 1974. Highway Post Office buses were used to replace Railway Mail Service in areas where train service had been discontinued.
Hyphen-hole perforation - perforation that utilizes the line method in cutting rectangular holes instead of the usual round ones. Some U.S. revenue stamps use this type of perforation.
HyPO - an abbreviation of the Highway Post Office Service, which operated from 1941 to 1974. Highway Post Office buses were used to replace Railway Mail Service in areas where train service had been discontinued.