Perfin

A 1951 perfin stamp of the UK (used by HMSO) showing front (top) and reverse (bottom)
A postal stationery envelope used from London to Düsseldorf in 1900, with additional postage stamp perfinned "C & S" identifying the user as "Churchill & Sim" per the seal on the reverse shown on inset
An unusual curved perfin INVENTION from Patent Agents G.F. Redfern & Co. of London, whose telegraphic address was also INVENTION
A large block of United States perfin stamps
A 1955 Canadian stamp with a CPR (Canadian Pacific Railway) perfin

In philately, a perfin is a stamp that has had initials or a name perforated across it to discourage theft. The name is a contraction of perforated initials or perforated insignia. They are also sometimes called SPIFS (Stamps Perforated with Initials of Firms and Societies).[1]

  1. ^ "Why does my stamp have a lot of holes in it?". Linns Stamp News. Amos Media Company. Jan 26, 1998. Retrieved 29 March 2020.