This refers to the uncut variety of keys that a locksmith (or anyone who copies keys) keeps on hand. Home-improvement stores may only stock a dozen or so types. Full-service locksmiths maintain inventories of thousands of types! Generally, if a key won’t even go into the lock, it is cut on the wrong blank.Key code
This refers to a series of letters or numbers found on some locks. In the case of office furniture and some padlocks, the number is stamped or printed right on the face of the lock. Some automobile manufacturers also stamp or print this number somewhere on the vehicle. Others vehicle manufacturers keep the key code on file and can look it up for the owner by the VIN number. (NOTE: The VIN is not a key code!) With a valid key code, a well-equipped locksmith can originate a key using books or software and special key-cutting equipment. This costs more than a simple duplicate key, but can be much less expensive than a service call.Key retaining
This is a feature that is available on several kinds of lock, including padlocks and some cabinet locks. If a lock is key retaining, the user cannot remove his or her key until they have locked the lock! It can be very effective in discouraging users from leaving things unlocked!Keyed alike
This refers to more than one lock that operate with the same key. If you have two padlocks that use the same key, they are keyed alike. If the same key operates your doorknob and the deadbolt above, they are keyed alike.Keyed different
This is the opposite of keyed alike. This refers to different locks requiring separate keys. Generally, your house should be keyed different than the house next door!