> For the complete documentation index, see [llms.txt](https://docs.wem.io/platform/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.wem.io/platform/wemreference/data-types/yes-no-boolean.md).

# Yes / No (Boolean)

### Description

The Yes/No datatype is used as Boolean (True/False) and has 2 specific values (Yes/True or No/False) besides the Unknown situation (which is not really a specific value), and is mostly used for conditional statements. When a YesNo field-value is displayed on a page, it will - based on the current language - display Yes or No or nothing when the situation is Unknown. In Expressions the True and False equivalents are implicated; Unknown should be regarded specifically if that situation may occur (check the [If-Unknown operator](/platform/wemreference/operators/if-unknown.md))

* `True` 
* `False` 
* `Unknown`

### Unknown

An unknown value can be written as `UnknownBoolean`.


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