After high school I got a job as a merchandiser for Pepsi Bottling Group. That's when I learned that both Pepsi and Coke distrubute Dr. Pepper in different areas.

If the 20 oz bottles in your area look like this you are in a Coke area, and if they look like this you are in a Pepsi area.

that's also why Dr Pepper can show up on fountains in both Pepsi and Coke aligned fast food places.