Template:Yesno/doc

evaluates any input and produces a normalized yes or nil output, based on the content of the input and several configurable options. It is not used in article prose, but in coding complex templates.

Usage
The template distinguishes five different types of input, supplied on the first unnamed parameter:
 * 1) Yes: Case-insensitive forms of ,  ,  ,  , and  ; e.g.
 * 2) No: Case-insensitive forms of ,  ,  ,  , and  ; e.g.
 * 3) Nothing: When the input is defined but either contains no value or consists of whitespace character only; i.e.   or
 * 4) Negation: When the input is either   or entirely missing; i.e.  or
 * 5) Anything else: e.g.

By default, the template returns "yes" in the first and last case but returns nil (blank, empty string) in the other cases.