A practical set of ready-to-use TLP references for security and risk practitioners.
 
The Traffic Light Protocol provides a simple, internationally recognized way to communicate how far information may be shared. Maintained by FIRST and widely understood across government, CERTs, critical infrastructure and industry, TLP replaces vague instructions such as “handle this sensitively” with a clear sharing rule that travels with the information. 
 
Why every security risk practitioner should understand TLP
 
Security risk management depends on information moving to the people who need it — without traveling further than it should. Threat intelligence, vulnerabilities, incident information, investigations, personal information and operational details routinely cross organizational boundaries, often under time pressure.
 
Getting the sharing decision wrong in either direction has consequences. Under-restrict information and sensitive material may reach people who should never have seen it. Over-restrict it and the people who need to act may never receive it. The governing principle is therefore simple: pick the narrowest label that still lets the recipient act. 
 
TLP is also easily misunderstood. It governs dissemination — who the recipient may tell. It does not, by itself, determine sensitivity, access or handling requirements, nor does it replace security classification, privacy requirements, legal privilege or technical controls.  
 
What’s included
 
This downloadable toolkit contains three print-ready resources:
TLP & Controlled Sharing — A3 Wall Chart — a large-format reference for offices, operations centers, security teams and incident response rooms.
TLP & Controlled Sharing — A4 Wall Chart — a convenient desktop or noticeboard reference covering the five markings, the four different information-sharing questions and the SRMBOK sharing decision.
Traffic Light Protocol — Practitioner One-Page Guide (A4) — a detailed working reference covering the markings, selecting the appropriate label, correct marking of emails and documents, and seven common mistakes that undermine TLP in practice. 
 
Together, the three resources provide both the at-a-glance reminder and the practical detail needed to apply TLP properly.
 
Print one for your desk. Put one on the wall. Keep the detailed guide close when the sharing decision actually matters.
 
Want to go deeper?
 
These resources are deliberately concise. TLP looks simple — and that is one of its strengths — but applying it well involves considerably more than knowing what RED, AMBER, GREEN and CLEAR mean.
 
The subject is explored in much greater depth in Julian Talbot’s The Traffic Light Protocol and Controlled Information Sharing: A Security Risk Practitioner’s Guide to Deciding Who Else May See It, including the judgment behind sharing decisions, the relationship between TLP and other information controls, and the difficult cases where a colored label alone is not enough.