We would like to inform you that Levi Strauss & Co. has registered various Tab trademarks, some are: the Tab with Levi's® written on it and the Tab without the word Levi's® on it; this is what we call the "blank" Tab. This blank Tab was registered to protect the Tab against imitators who use a tab on their products, but put a different name on it, they then claim that because there is a different name on it, it is not an imitation of our Tab. Our blank Tab trademark protects the shape of the Tab itself - regardless of what is written on it.
To maintain a trademark, it must be used. If you don't use a trademark for 5 years or more, someone else can file a "cancellation action" and have your trademark cancelled. The result is that it is no longer protected, and everyone can use it. In conclusion, about 10% of all our products have the blank Tab, the practice being to mix blank Tabs among our other Tabs.