BraneStorm is currently in very early development.

From BraneStorm

Allows value is a special property in Semantic MediaWiki with a built-in meaning: it lists one permissible value for a property.

For example, the page for a Problem severity property might contain: [[allows value::Enhancement]],[[allows value::Trivial]],[[allows value::Minor]], [[allows value::Normal]],[[allows value::Major]],[[allows value::Critical]]

This property is a special property in this wiki.