What does the letter "F" signify on a driver's license?

The letter "F" on a driver's license signifies that the driver is restricted to operating vehicles that are equipped with outside rear-view mirrors. This restriction is particularly important for safety, as the rear-view mirrors enhance visibility and help prevent accidents. Driving without these mirrors could lead to blind spots that the driver cannot compensate for, thereby increasing the risk of collisions.

The other choices do not accurately reflect the significance of the "F" designation. A provisional license does not require an "F"; rather, it has its own specific terms and limitations. The requirement to drive with a full tank of gas is not a standard policy or restriction associated with any driver's license. Additionally, the designation of a female driver does not play a role in the classification of driver's licenses and is not indicated by the letter "F". Thus, the correct interpretation of the "F" designation focuses solely on ensuring vehicle safety through appropriate equipment.