Template:Ns has subpages/doc

Detects whether the current or the given namespace has subpages enabled. Returns "yes" if it does, and an empty string otherwise.

This template can be substituted.

Usage

 * (''main space) →
 * (main space) →
 * (main space) →
 * (''main space) →
 * (main space) →
 * (main space) →