1.) a <#marginmark=marginal marking> used on <#flatplate=flat plates> indicating uniform vertical spacing between columns of <#stamp=stamps>.  This marking was intended to assist operators of <#perf=perforating> equipment.  2.) the prefix letter used by the <#abnc=American Bank Note Co.> in front of the <#pn=plate number> on its modern <#stamp> production.

a <#webfed>, eight color press (three <#intaglio> colors and five <#gravure> colors) in use at the <#bep=BEP> from 1973 to 1993.  It created <#pane=panes> with <#floatpn=floating plate numbers>.

Added to Color tagging.  See also <#phosink=Phosphored Ink>.

see <#aef=American Expeditionary Force>.

see <#amf=Air Mail Field>.