A "no smoking sign" is a visual indicator that prohibits smoking in a specific area. These signs are commonly found in public places such as restaurants, airports, and offices to promote a healthier environment. They often feature a cigarette icon crossed out with a red circle, making the message clear and easily recognizable. The purpose of a no smoking sign is to protect individuals from the harmful effects of secondhand smoke, which can lead to various health issues. Additionally, these signs help maintain cleanliness and reduce fire hazards associated with discarded cigarettes in areas like parks and buildings.