What motor vehicles are subject to the no-overtaking rule indicated by this sign?

The sign shown prohibits overtaking for certain vehicles. Normally, the primary sign means "No overtaking by trucks." The additional sign below with "auch" (meaning "also") indicates that the no-overtaking rule extends to the vehicles shown there as well.

In this case, the additional sign shows a bus or coach. This means that coaches or buses are also subject to the no-overtaking rule indicated by the main sign, just like trucks.

Cars without trailers and single-track motor vehicles (like motorcycles) are not affected by this particular no-overtaking rule here. So, the rule specifically applies to larger vehicles such as trucks and coaches or buses, ensuring road safety by restricting overtaking maneuvers for bigger, slower vehicles on certain road stretches.