Computer-telephony events are initiated by a user operating a computer terminal to control, through a computer-telephony controller, operation of a communications terminal. The computer-telephony controller receives from a first computer terminal a request for a first computer-telephony event; in which the request for the first computer-telephony event comprises a label value. The computer-telephony controller refers to a mapping between the label value and an identifier of a communications terminal; and initiates the requested first computer-telephony event controlling operation of the communications terminal. The computer-telephony controller then receives, from second computer terminal 2B, a request for the label value. The computer-telephony controller authenticates the label value request and provides to second computer terminal the requested label value. The computer-telephony controller then receives from second computer terminal a request for a second computer-telephony event, in which the request for the second computer-telephony event comprises the label value. The computer-telephony controller refers to the mapping; and initiates the requested second computer telephony event controlling operation of the communications terminal.