If this function has been configured (contact System Support), you can lock other telephones to prevent unauthorized use and then unlock them again later. 

You can use this function to unlock the telephone for users who have locked their telephones and then forgotten their PINs. 

Press the key. The LED lights up. 

Confirm. 

Enter the code. 

Enter the internal number of the telephones that you want to lock or unlock. 

Confirm. 

Enter the code.