<boolean>
The <boolean> element was deprecated in DITA version 1.1.
         It was originally intended to express one of two opposite values, such as yes / no
         or on /
         off.
         
      
      note
This element is deprecated. It is functionally equivalent to 
            <state
                     value="yes|no"/>, which is recommended as its replacement in all
                  cases.
               Content models
See appendix for information about this element in OASIS document type shells.
Inheritance
- topic/boolean
Example
She said "<boolean state="yes"/>" when I asked her to marry me!
Attributes
The following attributes are available on this element: Universal attribute group, @outputclass, and the attribute defined below.
- @state (REQUIRED)
 - The state of the <boolean> element. Allowable values are "yes", "no", and "-dita-use-conref-target".