A type of hand-sorted edge-notched punched-cards, typically manipulated with a "needle". Often organized by some key such as by author, chemical compound name, or some other dominant interest of the system designer. Cards need not be filed in any order.
BenTremblay edge-punched cards to sort using knitting-type needles (60s ... do the physics).
One WikiZen implemented an inventory control system using it in 1971, with one hardware refinement. The order book got to be rather a thick deck, such that getting the notched cards to drop at each stage of sorting grew more difficult. Using one of those little red Wen electric engravers with one of the sorter needles TIG welded onto the business end, in place of the carbide point allowed the cards to be vibrated, fanned them out, and caused the ones notched at that hole to drop promptly.
The system had four holes per digit, numbered (as you might not expect) 7-4-2-1. That way, no decimal digit required more than two punches to encode it.
(NOT related to the KanbanSystem or kanban cards. In spite of the fact that both use cards.
Also not really related to HollerithPunchCards, which are not edge-punched.)