Many times, the top of your key has numbers or letters stamped or engraved. What do those mean?
There are typically 2 different types of “codes” stamped on a key.
DIRECT CODE

A “Direct Code” is the exact numbers related to the cuts or the depths of each valley in your key. This is typically used to identify a specific key and how the lock should be combinated to allow the key to operate. For the most part, this happens from the lock manufacturer. You’ll see this inside a box of door locks at a hardware store or inside a lockbox on your locksmith’s shelf.
Loc-Doc Security does not distribute these keys. We cut a new key on a blank without those numbers. With those numbers alone, another key can be made without your knowledge or permission.
BLIND CODE

Blind codes are used for Master Key Systems and File Cabinet Locks. In most cases, a blind code is a reference point for a locksmith or manufacturer to identify the key and make additional copies or identify the locks that the key operates.