His Bumper Sticker
Then it clicked: William realized the reason the officer knew about his service. He had forgotten about the bumper sticker he had on the back of his pickup truck. Anyone who saw it would immediately know that he had previously served in the army.
A Symbol
A lot of times, army veterans put stickers on their cars. For William, it’s not uncommon that another driver will wave or honk their horn as a way to thank him for his service. However, he had never been stopped by a policeman for this reason.