This template has a corresponding Lua module Module:Yesno, but does not invoke its functions.
This template invokes the following functions: _yesno from Utils.

{{Yesno}} evaluates any input and produces true or false, based on the content of the input and several configurable options. It is not used in article prose, but in coding complex templates.

Since Module:Yesno cannot be {{#invoke: }}d directly, a wrapper function in Module:Utils is used to access it.