Hoi,
Dan kijk ik ook gewoon in de wiki...

https://wiki.openstreetmap.org/wiki/Street_parking#Loading_zones_and_other_action-based_parking

Hier een voorbeeld parking:side:restriction=loading_only

Implies, that parking is not allowed, but stopping is allowed as long as loading/unloading is in progress (or a signposted time limit has expired). 
