Perfin

Perfins is slang for stamps with perforated initials. These are used to identify business usage to prevent theft of stamps. They are also used by government agencies for the same reason but are then often considered official stamps. These also refer to revenue stamps cancelled thus.

These can be a simple arrangement of letters but may include symbols/artwork. They can be upside down, reversed, sideways, shifted, etc. and can be found on a variety of issues and values.  File:Canada air OHMS perfin.jpg|Canada O.H.M.S. official perfin. File:Bavaria E perfin.jpg|Bavarian official for the railways (E="Eisenbahn") File:France G perfin.jpg|France "G" (Gentil & Cie) File:Australia OS perfin.jpg|Australia O.S. official perfin. File:US AR perfin.jpg|US "AR" (American Radiator Co.) 