Loiding

= Loiding =

Loiding (or carding) is a bypass technique that uses a flat object, such as a credit card, to retract spring-biased latches. The flat object, referred to as a shim or loid, is slid between the latch and strike plate and used to retract the latch. Modern spring-latch doors use a deadlatch or dead locking plunger to prevent loiding. Loiding may also be referred to as shimming, though that is a more generic technique used to open various types of locking mechanisms.

The term loiding comes from celluloid, sheets of which were cut down to size and used for entry. It became known amongst many London criminals as a loid.

Loiding is generally a surreptitious attack but certain tools and techniques may leave behind forensic evidence.