The product's name came from the fact that the "dnL" logo is the "7 Up" logo rotated 180°. As such, the product itself was, in many ways, the polar opposite of 7 Up: while 7 Up is caffeine-free, colorless, and comes in a green bottle, dnL contained caffeine, was colored vaguely similar to the green of 7 Up's bottle, and came in a clear bottle. And while 7 Up has a fairly standard lemon-lime flavor, dnL was a stronger lime-lemon/citrus flavor.
The limited amount of marketing created for dnL focused on its "upside-down" theme, including its slogan, "Turn your thirst upside-down." The color was also similar to Pepsi's Mountain Dew soft drink, and, like Mountain Dew, was developed primarily to compete with The Coca-Cola Company's Sprite, Fanta, and Mello Yello.
When this soda got relaunched in select cities, it became DNL in all caps with the logo.