Every person who will be working on the equipment applies a lock or tag to each energy isolating device. For complex equipment with many energy sources a group lockout is permitted. After locks are applied, an attempt to re-start the equipment must be made to verify the equipment cannot be restarted before servicing begins. After servicing, each person who placed a lock or tag must remove it before the equipment is started. These are training, written procedures, and inspections.
Authorized employees are people who do the maintenance or servicing work.
Affected employees are people who may be affected by or work near equipment which is locked or tagged out. Affected employees are not permitted to perform servicing or maintenance work which requires a lockout or tagout. They are only useful if all the information they contain is correct. Typically it is an authorized employee who is not directly involved with the procedure being inspected. Never take a shortcut when it comes to your safety, especially when you're working with hazardous energy sources.