1.8 Toll Restriction (TRS)/Call Barring (Barring) Features108 Feature Guide1.8.3 Extension LockDescriptionAn extension user can change the TRS/Barring level of the telephone ( 1.8.1 Toll Restriction(TRS)/Call Barring (Barring)) so that other users cannot make inappropriate trunk calls. Anextension personal identification number (PIN) is used to unlock the telephone ( 1.26.1Extension Personal Identification Number (PIN)).This feature is also known as Electronic Station Lockout.Conditions• This feature also restricts changing the FWD destination. ( 1.3.1.2 Call Forwarding(FWD))• Remote Extension LockOverrides Extension Lock. If an extension assigned as the manager sets RemoteExtension Lock on an extension that has already been locked by the extension user, theuser cannot unlock it. If a manager extension unlocks an extension that has been lockedby the extension user, the extension will be unlocked.This feature is also known as Remote Station Lock Control.• TRS/Barring LevelCOS programming determines the TRS/Barring level for Extension Lock ( TRS/BarringLevel for Extension Lock [510]).User Manual ReferencesUser Manual1.5.3 Preventing Other People from Using Your Telephone (Extension Lock)2.1.1 Extension Control