Acceptance Register

The Acceptance Register lists the Sources/Threats, Vulnerabilities, and Impacts that don't have defined controls. 

Risk acceptance

Risk acceptance is not really a mitigation strategy because accepting a risk does not reduce its effectiveness. However, risk acceptance is a legitimate option in risk management. There are various reasons why companies may choose risk acceptance in certain situations. The most common reason is that the cost of other risk management options, such as avoidance or limitation, may outweigh the cost of the risk itself.