Why is it C1M after downgrading?

[MacJoseph]

After a driver's license is downgraded, it is usually reduced to C1 because the C1 license can be used for life as long as the physical conditions permit. However, it often becomes C1M because the driver's license has an additional M-class vehicle endorsement, and there is no further downgrade option for the M-class. Therefore, it naturally remains included. The C1M license can be considered a combination of the C1 and M licenses, adding the M-class vehicle endorsement to the C1 driver's license. The C1 license allows driving small cars, while the M-class endorsement permits the operation of wheeled self-propelled machinery. C1: Small cars, small automatic transmission vehicles, low-speed trucks, and three-wheeled vehicles. Small and micro passenger vehicles, as well as light and micro cargo vehicles; light, small, and micro special-purpose vehicles; small passenger vehicles with a seating capacity of 9 or fewer people. M: Vehicles, tire cranes, road rollers, tractors, harvesters, and specialized construction machinery.