Alternate Work Site

No definition is given in NIST SP 800-171r3. The term is attested in use at 4 citations in that document; a definition is pending curation.

A recognized security-control category covering any approved location where an employee conducts official organizational work outside the organization's primary or owned facility — including private residences, satellite offices, co-working spaces, government facilities, and hotel or similar transient environments. It is distinguished from "alternate processing site" (a DR/BCP concept for relocating IT systems) and from "remote access" (a network-layer concept): its focus is on the physical and operational security posture of the place of work itself. Frameworks such as NIST SP 800-53 (PE-17) and NIST SP 800-171 (3.10.6 / 03.10.06) treat it as a named control within the Physical Protection family, requiring organizations to enumerate approved sites, apply organization-defined security requirements to each, assess control effectiveness, and maintain an incident-reporting channel for personnel working at those locations.