Post-dial DTMF strings allow you to append PINs or other ID numbers to a particular contact number, using the comma (',') character to represent 2-second pauses in sequence.
It's particularly valuable if you have standard conference bridges you repeatedly call into wherein you need to enter a PIN or ID number to access the bridge. In this case, you can use commas to represent the gap in time where the conference recording is "asking you to enter your PIN" with the numerical string you've entered automatically executing after the set duration.
Set Up Post-Dial DTMF String for a Contact
When editing or creating a new contact, enter a comma (',') to represent a 2-second gap in sequence after the number itself. Multiple gaps can be added:
For example, if you frequently call into a conference bridge with a number of (555)555-5555, wherein you need to enter a PIN of '1234' six seconds after the call connects, and '5678' eight seconds after the call connects (two separate PINS), you would enter the contact number as (555)-555-5555,,,1234,,,,5678.
In that way, you only have to click 'Call' to access this conference bridge; you don't have to enter both PINs every time to join.