Positional master keying is used in systems where split pins are not practical. For example, some dimple key systems and some magnetic key systems. The official Locksmith Dictionary from the LIST Council shows the following definition as of 05/2025.NOTE: This is not "rotating constant" master keying.
positional master keying
n. a method of master keying typical of certain binary type disc tumbler key-in-knob locks and of magnetic and dimple key cylinders. Of all possible tumbler positions within a cylinder, only a limited number contain active tumblers. The locations of these active tumblers are rotated among all possible positions to generate key changes. Higher level keys must have more cuts or magnets than lower level keys.
This chart helps us understand the process
The master key succeeds because it contains both 1’s and 2’s in the correct positions.
Change keys work within assigned positions but can’t be substituted as master keys.