Controlled unclassified information
Also known as CUI
Government information that is not classified but still requires protection under law or policy.
It covers technical drawings, specifications, export-controlled material, and much of what flows down through defense contracts. It is not secret, but it carries handling obligations.
Identifying where it actually lives is the hard first step, because it arrives by email, sits in engineering shares, and gets copied into project folders without ever being marked.
Where this comes up
Controlled unclassified information sits inside our compliance and frameworks work. If you are trying to work out what this means for your own environment rather than in the abstract, that is the page worth reading next, and a short call will get you a straight answer faster than either.