The TLP (Traffic Light Protocol) is a simple color-coded scheme that governs how shared information may be distributed. TLP:RED restricts information to direct recipients only. TLP:AMBER allows sharing within the recipient’s organization. TLP:GREEN permits sharing with the broader community, and TLP:CLEAR allows unrestricted public distribution. In ISMS practice, TLP is widely used when exchanging security information with external parties such as CERTs or industry groups. The protocol is maintained by FIRST and internationally recognized.