@yardtalkhbcu October 17, 1979
Apparently everyone prior to that date had a terrible education.
All those teachers prior to that must have done it for free.
@NotK_US After the master code is changed, the lock can never be programmed with an MRC. Conversely, when an MRC is programmed into a lock, it is always present. It cannot be deleted or changed.
@NotK_US Before any buttons are pressed, you need to make some decisions. The first is whether or not your lock is to have a management reset code, also known as the MRC. This code must be programmed into the lock before the master code is changed for the first time.