Kolkata: The transport department has reinforced the rule that two-wheelers used for goods and passenger transport must have commercial registration. In a notification, transport secretary Saumitra Mohan reiterated the ban on non-transport vehicles under Online Digital Two-Wheeler Transport Aggregator system, including bike-taxis. The guidelines reiterate such two-wheelers must have valid papers and certificates, riders must hold licences, one passenger is allowed at a time, and passengers can carry luggage up to 10 kg.