A registration pin is a device intended to hold a piece of film, paper or other material in place during photographic exposure, copying or drawing.
Registration pins are used in offset printing and cartography, to accurately position the different films or plates for multi-color work.
Also, in traditional, hand-taped printed circuit board artwork, usually at two or four times actual size.
[citation needed] Western professional cameras provided to the East during World War II's Lend-Lease program were usuallt converted to KS pins by the receiving country.
The above description applies to professional applications, which is generally taken to mean film gauges larger than 16mm (i.e., 35mm and 65/70mm).