http://www.w3.org/2001/XMLSchema#boolean

used by 14:

• bathing-water-surveys-guideline-standards-1994-to-2011
• courts-thesaurus
• educationalprograms_sisvu
• education-openuplabs
• eea-rod
• eunis
• lexinfo
• lexvo
• my-experiment
• open-energy-info-wiki
• portal-turismo-de-la-rioja
• transport-openuplabs
• uniprot-metadata
• vivo-cu-boulder