Final answer:
The regulation that defines Federal Contract Information is found in the Code of Federal Regulations (CFR), specifically in Part 52.204-21 in Title 48 of the CFR.
Step-by-step explanation:
The regulation that defines Federal Contract Information is found in the Code of Federal Regulations (CFR). The CFR is a collection of regulations established by federal agencies to implement and enforce the law. Federal Contract Information is defined in different parts of the CFR depending on the specific context. For example, in Title 48 of the CFR, specifically in Part 52.204-21, it provides the definition of Federal Contract Information related to the safeguarding of controlled unclassified information.