If a customer brings in a vehicle without a license plate, what should be entered?

When a customer brings in a vehicle without a license plate, entering "none" is the most appropriate action. This designation indicates the absence of a license plate on the vehicle, reflecting its current status. It's essential for maintaining accurate records of the vehicle's inspection process.

The other choices do not accurately address the situation of a vehicle without any form of identification or registration. A temporary tag issued or a dealer’s temporary license implies that some form of temporary registration exists, which contradicts the scenario presented. A standard inspection number, while part of record-keeping, does not substitute for identifying the lack of a license plate and would not provide clarity regarding the vehicle's registration status. Thus, the designation of "none" serves as a clear and appropriate entry for this circumstance.