Classified

Classified describes information or material officially restricted from public access to protect national security, public safety, privacy, or economic interests. It can apply to documents, data, media, or communications that require controlled handling. The term also refers to the process of designating such materials.

In government and military contexts, classification levels vary by country but commonly include Top Secret, Secret, and Confidential. Some systems add categories like sensitive compartmented information. Access is limited to individuals with approved clearance and a legitimate need to know, and handling follows strict marking, storage, and transmission controls. Declassification can occur automatically or by policy after a set period.

Classification aims to protect sources and methods, national security, privacy, and proprietary information. It relies on laws, executive orders, and organizational policies. Disclosing classified material can carry criminal penalties, disciplinary action, or other consequences.

Classified ads, by contrast, are listings in newspapers or online that advertise goods, services, jobs, or real estate. They are organized by category, may be free or paid, and typically include contact information for responders.

In broader use, "classified" also describes information kept confidential in business or research contexts to safeguard intellectual property, trade secrets, or personal data.