MediaWiki:Apihelp-query+pageprops-param-prop
Only list these page properties (action=query&list=pagepropnames returns page property names in use). Useful for checking whether pages use a certain page property.
wiki.Alumni.NET - Your Location Information Resource
Only list these page properties (action=query&list=pagepropnames returns page property names in use). Useful for checking whether pages use a certain page property.