DTMF, or dual-tone multi-frequency is the sound you hear when you dial different numbers on your phone. This generates a code that is used to signal the user’s intended action when the different numbers are dialled in combinations.
Other than calling people, when you are on a call you can dial different DTMF short codes to trigger different actions. Below is a list of DTMF codes that you can use on your phone.
NOTE: DTMF codes work with physical hardware and with virtual devices (Softphone App, UC Desktop App, MS Team Dialpad).