Discretionary Access Control. Check the validity of credentials given at the discretion of the user (e.g., username and password).
Downhill Assist Control. Driver-operated, DAC slows the vehicle on slippery slopes to help regain control and prevent vehicle run-away . It uses individual wheel-direction sensors to maintain slower controlled speeds, weather going forwards or backwards . It can be activated when the gear is in neutral.
discretionary access control. Restricts access to objects based on identity and/or group membership. The controls are discretionary in the sense that a user with a certain access permission (for example, an object owner) is capable of passing access permission on to any other user, such as with the grant command.