A barrier whose performance has been verified by satisfying placement acceptance criteria through evaluating data collected during installation. NOTE A confirmed barrier has a lower level of assurance than a tested barrier. EXAMPLE A barrier that is intended to resist pressure from below during its service is tested successfully after installation with pressure from above. The barrier in this scenario is considered to be a confirmed barrier but does not meet the definition of a tested barrier because it was not tested in the direction of flow in service.
Source: API RP 96, Deepwater Well Design and Construction, First Edition, March 2013. Global Standards