When you are handed a padlock without any identification on it, the main identifier we use is the lock's serial number.
The serial number is the middle row of numbers on the back of the lock:
It's the middle row of numbers; donThis lock's serial, for example, is 57184697. Don't worry about the other numbers/letters. This lock's serial, for example, is 57184697.
In Oliver, returning the padlock will bring up who the lock was borrowed out to in Oliver, as well as the combination.
The serial number is under the Barcode heading, and the combination is under the Classification heading.
You can also see who the lock was borrowed out to under the Borrower heading.