Protected Critical Infrastructure Information
The Protected Critical Infrastructure Information (PCII) Program is an information-protection program that enhances voluntary information sharing between infrastructure owners and operators and the US government. PCII protections mean that homeland security partners can be confident that sharing their information with the government will not expose sensitive or proprietary data.
NIST Publication on Controlled Unclassified Information (UCI). 
- Security of Critical Infrastructure Bill 2018
- PCII Program, DHS, United States
- NIST SP800-171 - Protecting Controlled Unclassified Information in Nonfederal Information Systems and Organizations (2015).