There are very few policies which apply across all Wikia. These can be found on the Central Wikia at Wikia:Category:Policy.
Often when creating new pages to give a framework it is tempting to copy paste from existing sources such as wikipedia. However, this wiki aims to be a standalone source of original material, so any material added that has been directly lifted from somewhere else is liable to be removed.
The only sources of canonical in-universe information are the films directed by Christopher Nolan, and scripts written by him.