Alternative Compensatory Control Measures (ACCM).
documentedgovernment_studyGovernment Concealment & Secrecy Architecture
A control tier BELOW SAP/SCI: any Original Classification Authority can stand up nicknamed access controls when need-to-know can't be enforced but a SAP 'isn't warranted'. DoDIG-2015-070 found ACCM used to hide activity that should have been SAPs, evading SAP-tier congressional reporting.
The under-the-radar concealment tier with NO central registry (unlike SAPs' SAPCO). Documented (DoD IG) as an oversight-avoidance vehicle -> arguably zero routine congressional visibility. A program can live here specifically to avoid the Gang-of-Eight floor.