Not suitable/safe for work (NSFW), not work-suitable/safe (NWS), or not school-suitable (NSS) is Internet slang or shorthand. Typically, the NSFW tag is 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 material such as pornography or profanity, which the viewer may not want to be seen accessing in a public or formal setting such as at work.
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 explicit content. Companies and schools frequently adopt such policies because they regard the presence of sexually explicit content as a misuse of company property (or education resources) and, potentially, a violation of sexual harassment policy.
Determining a site to be NSFW is invariably subjective. The less frequently used warnings PNSFW (Probably/Possibly Not Safe for Work), LSFW (Less Safe for Work), TSFW (Technically Safe for Work), and PNFO (Probably Not for the Office) are sometimes used to indicate content possibly considered salacious (lustful) by certain censors, such as images of underwear or swimwear models, or a news story about sexual issues that does not contain explicit images. NSFW is also sometimes used to refer to any media that produces sound, such as a game or video file; the implication being that the noises may alert others in the vicinity that the user is taking a break with entertainment materials instead of working.
NSFW can be used flippantly under the same circumstances, to mean "Now Show Friends and Workmates".[1]
The opposite, SFW (safe for work) is sometimes used when the context or the URL itself would otherwise indicate that something is NSFW; for example:
http://www.example.com/pussy.jpg (SFW) (SFW)
might link to a picture of a cat (SFW) rather than female genitalia (NSFW).
On November 28, 2007, Fark.com founder Drew Curtis filed an application[2] to trademark the phrase, but registration was denied.[3]