Over the holidays, I learned that our alarm system contains a default code that disables the alarm. A duress code is designed to be entered on the alarm keypad in the event that an attacker or robber ambushes you at home and forces you to disarm the system. It might be a good idea to ask your alarm company if your system has a default “duress code”: 2-5-8-0, the four digits that run straight down the middle of the keypad.”]
Source: https://krebsonsecurity.com/2013/01/does-your-alarm-have-a-default-duress-code/