prefix letter used by <#dittler=Dittler Brothers, Inc>. in front of the <#pn=plate number> on its modern <#stamp> production.

<#webfed> press with both <#offset> and <#intaglio> capacities in use at <#bep=BEP> 1984-1996.

see <#dpo=Discontinued Post Office>.

a <#precancel> stamp marked by the user with the month and year of use.

unit of the post office that receives undeliverable mail with no return address, and attempts to return it to the sender.  Until 1917 the Dead Letter Office was located in Washington, D.C.  In 1917 its work was decentralized, with branches in various cities.