Edge-notched card

Cards existed in many variants, with differing sizes and numbers of rows of holes.

The center of the card could be blank for information to be written onto, or contain a pre-printed form.

To record data, the paper stock between a hole and the nearest edge was removed by a special notching tool.

The Stasi used edge-notched cards (German: Kerblochkarteikarten) from 1965 to index information including details of staff, crimes, people under surveillance, and vehicles.

Cards often stored information about the occupation, interests, and suspected political affiliations of those recorded.

[13] The cards became obsolete for data storage by 1980 with the introduction of computer databases, but were retained and used to retrieve information after this date.