Not suitable/safe for work or NSFW is an Internet slang or shorthand tag used in e-mail, videos, and on interactive discussion areas (such as Internet forums, blogs, or community websites) to mark URLs or hyperlinks which contain nudity, intense sexuality, profanity, violence/gore or other disturbing subject matter, which the viewer may not wish to be seen accessing in a public or formal environment including a workplace or school.
Determining a site to be NSFW is invariably subjective, and poses challenges for academics who study sexuality. The difficulty in identifying such content objectively has led to the creation of online tools to help individuals to identify NSFW content.
NSFW has particular relevance for individuals making personal use of the Internet at workplaces or schools which have policies prohibiting (even inadvertent) access to sexually provocative subject matter.
On November 28, 2007, Fark.com founder Drew Curtis filed an application to trademark the phrase, but the application was abandoned. Conversely, the term Safe For Work, sometimes abbreviated to SFW, is used to label material that may have a questionable title or include subjects that could be NSFW, but are not.
In an allusion to the established use of the term on the Internet, Not safe for life (NSFL) generally refers to subject matter that might not be in the interest of a person to view regardless of location and potential coviewers for being horrifying, disgusting, offensive, or even mentally disturbing to the viewer themselves. Usually it refers to depictions of real graphic violence ("gore"). Many content-aggregator sites including Reddit, video-platforms such as LiveLeak and imageboards such as 4chan have their own subsites which are dedicated to or allow such content – often with the requirement that such material be marked as such which is often done via a NSFL tag.