A named tag set for metadata used to populate a security category label field that "segments" an IT resource per policy by indicating that access and use is restricted to members of a defined community or project. (HL7 Healthcare Privacy and Security Classification System) Usage Note: This is the healthcare analog to the US Intelligence Community's concept of a Special Access Program. Compartment codes may be used in as a field value in an initiator's clearance to indicate permission to access and use an IT Resource with a security label having the same compartment value in security category label field. Map: Aligns with ISO 2382-8 definition of Compartment - "A division of data into isolated blocks with separate security controls for the purpose of reducing risk."