Comment by izoow

There's even more options apparently :)

A Boolean represents a true/false value. Booleans are formatted as English words (“true”/“false”, “yes”/“no” or “on”/“off”) for readability and may be abbreviated as a single character “y”/“n” or “Y”/“N”.

Regexp: y|Y|yes|Yes|YES|n|N|no|No|NO|true|True|TRUE|false|False|FALSE|on|On|ON|off|Off|OFF

(https://yaml.org/type/bool.html)