A way of linking wiki pages to another, using [[double square brackets]] instead of the CamelCase way.
...it was the switch of the large Wikipedia wiki to so-called "free links", words that are put in [[double square brackets]],which encouraged wiki developers to look for alternative solutions. Various wiki engines use single brackets, curly brackets, underscores, slashes or other characters as a link pattern. Links across different wiki communities are possible using a special link pattern called InterWiki.
---> see CamelCase , http://en.wikipedia.org/wiki/Wiki