Abbreviations, acronyms, and memes fall in and out of fashion on the Internet all of the time. Today's "I can has cheeseburger?" is often tomorrow's "All your base are belong to us." Some stand the test of time, including phrases like "not safe for work" (NSFW), which is used in forums, chatrooms, and blogs across the world to warn folks that something they're about to see could give the boss fits. Late last month, offbeat news site Fark.com filed for a trademark on the phrase with the US Patent and Trademark Office.

Fark is seeking exclusive rights over the phrase as it's currently used across the Internet. Here's what the trademark would cover, according to the application:

Entertainment Services namely providing a web site featuring photographic, audio, video and prose presentations featuring comedic captions regarding current events and online discussions and/or reviews of web materials of an adult nature; Entertainment services, namely, providing a web site featuring musical performances, musical videos, related film clips, photographs, and other multimedia materials; Entertainment services, namely, providing on-line reviews of photographs and /or web postings of an adult nature.

Given the wide use of the term, any trademark would likely be very difficult to enforce. Trademork, which unearthed the application, points out that a number of sites use NSFW as part of their brand or to label adult content. Those include NSFW.com, TotallyNSFW.com, and the NSFW Comic Strip, as well as the NSFW sections of Atom Films and Funny or Die.

The fact that NSFW is a part of the Internet vernacular may work against Fark's application, and should it be awarded, enforcement is likely to be both expensive and difficult.