I work in the railcar industry as a Tank Car Designer. All railcars are assigned a Reporting Mark and Car Number identifying car ownership and it's number. My employer gave all of the employees in our office the same water bottle. So as a novel way of identifying my bottle, I used my initials,"X" and my start date with the company in the style of a Reporting Mark and Car Number. It's placed on both sides of the bottle just as it is on a railcar.