Coca-Cola just announced it is introducing Coke Zero in India, which will make it the sub-brand’s 149th market in the world, a truly remarkable reach.

As the popular Coke Zero brand is approaching its tenth anniversary in the U.S., it seems like a good time to explore Coca-Cola’s trademark position in COKE ZERO and COCA-COLA ZERO here in the U.S., especially given the news last week that the beverage giant escaped a trademark infringement suit over the marks in the Northern District of Illinois.

After looking into that case, I was surprised to see, as long as Coke Zero has been on the market  — none of the ZERO marks sought by Coca Cola have registered, all seventeen remain pending in the U.S., including COKE ZERO, COCA-COLA ZERO, SPRITE ZERO, PIBB ZERO, VAULT ZERO, and POWERADE ZERO, among others.

In fact, the series of ZERO marks has been the subject of at least two very large and significant consolidated trademark oppositions at the TTAB of the USPTO, since 2007, and the one brought by Royal Crown Company (RC) remains active — in fact, the case was fully briefed this past summer and Coca-Cola requested just last month that the Board schedule final oral argument in the case. In the Royal Crown opposition, RC contends that Coca-Cola must disclaim any exclusive rights in the term ZERO, as that term is either generic for zero calorie beverages or merely descriptive without any secondary meaning or acquired distinctiveness.

The other consolidated opposition was brought by AMBEV, back in 2007, also asserting mere descriptiveness and lack of secondary meaning, but AMBEV’s consolidated opposition was dismissed just over two years ago by the TTAB, as the Board was convinced at that time, Coca-Cola had established acquired distinctiveness in its ZERO marks based on the factual record developed in that case.

So, if ZERO marks can be owned in connection with beverages, how did Coca-Cola escape liability in the trademark infringement suit in the Northern District of Illinois last week? The plaintiff in that case had asserted exclusive common law rights in NATURALLY ZERO for spring water, but it admitted to gross sales of $150,000 between 1998 and 2004, no production or sales after 2004, and no attempt to resume sales until 2010, well after Coca-Cola had launched its ZERO series of beverage products in the U.S.

Moreover, the plaintiff there had admitted NATURALLY ZERO communicated “no calories, you know, a drink about nothing . . . .” As a result, the court granted summary judgment to Coca-Cola, ruling as a matter of law that the plaintiff’s merely descriptive mark had not acquired distinctiveness, and even if it had, the claimed NATURALLY ZERO mark had been abandoned.

Coca-Cola has been careful to straddle the fine lines of trademark protectability, since it has found itself on both sides of trademark disputes. Taking the position that ZERO is descriptive permitted Coke to defend the above-referenced trademark infringement challenge, while at the same time maintain that Coca-Cola’s juggernaut of marketing, sales and promotion established that is has acquired distinctiveness in its ZERO marks.

Yet, it remains to be seen whether Coca-Cola will prevail in the consolidated opposition brought by Royal Crown Company, perhaps its most significant challenge to date regarding the ZERO series of marks. I’ll have to say, RC’s Trial Brief makes out a pretty strong case for finding ZERO generic for zero calorie beverages. In other words, is ZERO like LIGHT for beer, STONE OVEN for pizza — basically denoting the name of a product category instead of a source identifier?

In the end, given the Board’s recent genericness rulings regarding Subway’s claimed FOOTLONG mark, and Frito-Lay’s successful PRETZEL CRISPS challenge, it will be worth watching to see whether the Board finds that “ZERO” primarily means Coke or just a soft drink having “no calories, you know, a drink about nothing . . . .”