UK Security: Vetting, Classifications, and Caveats
An Introduction
For those who have lived inside secure environments, the memory of clearance is rarely limited to a single word such as SECRET or TOP SECRET. What lingers instead is a dense overlay of markings, caveats, compartments, and dissemination rules—an entire grammar of trust that governed not just how sensitive information was, but who could see it, why, and under what conditions.



