What Does Not Safe for Work Mean?
Not safe for work (NSFW) is an Internet slang term used in email subject lines, online discussion boards, online videos and other Internet media. It is meant to warn a potential viewer that the content is not suitable for viewing in a work environment or near children, usually because because of sexual or other explicit content.
NSFW may also stand for "not suitable for work".
Techopedia Explains Not Safe for Work
Many office employees also use their office email addresses to send non-work-related content to friends and coworkers, open their personal email on company time, or just browse non-work-related websites. However, some content, including inappropriate or racist humor, sexually explicit content, or even just overly personal content, can get an employee into trouble at work.
The phrase NSFW was coined to warn people that the content they are about to view could get them into trouble if they are caught by a manager or supervisor. Many organizations specifically prohibit the dissemination and consumption of sexually explicit or disturbing content. Such material is regarded as a misuse of company resources, and in some highly litigous countries such as the U.S. there could be real fear from top management of the company being sued on sexual harassment grounds by employees who have received such material.
What is and isn’t NSFW is subjective, although there are usually clear boundaries in terms of content that would not be acceptable in any workplace.