A non-transitory computer-readable information storage media having stored thereon instructions, that when executed by a processor, cause to be performed a method for operating a telephone system having at least two telephony terminals where functional data can be transmitted through special functions of the telephone system comprising:
- allocating a second telephony terminal to a first telephony terminal through selection from a list;
- assigning a respective function to an action key of the first telephony terminal depending on the status of the first or second telephony terminal;
- and
- triggering the respective function by actuation of the action key of the first telephony terminal.