c8fee158_pl____h_selectBooleanCheckbox___Description
[Name] required [Type] boolean [Supports EL?] Yes [Description] 
A boolean value that indicates whether an input value is required. If this value is true and no input value is provided by a postback operation, then the "requiredMessage" text is registered as a FacesMessage for the request, and validation fails. Default value: false.
Apache MyFaces JSF-2.0 Core Impl - <h:selectBooleanCheckbox>