I recently booked some backcountry campsites in a national park (in the USA). My plan is to hike from one town to another over a few days, and the camp sites are by reservation only. These sites are not accessible by road. When i made the reservation, it required me to put in the make, model, color, and license plate of my car. I will not have a car with me, nor could I (since there are no roads), yet this information was required of me (no opt-out).