"Query depth" is a predefined property that informs about the depth of a query and is provided by Semantic MediaWiki. It is a numerical value computed on the basis of subquery nesting, property chains, and available description elements with the execution of a query being restricted by the
$smwgQMaxDepth configuration parameter. This property is pre-deployed (also known as special property) and comes with additional administrative privileges but can be used just like any other user-defined property.