Comment by 411111111111111

specifically according to https://yaml.org/type/bool.html:

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

Not all parsers support all of these options, but true|false is always supported as YAML is a superset of JSON which makes these mandatory.