Template:Ns has subpages - Wikipedia
This template is used in system messages, and on approximately 2,920,000 pages, or roughly 5% of all pages.Changes to it can cause immediate changes to the Wikipedia user interface.
To avoid major disruption and server load, any changes should be tested in the template's /sandbox or /testcases subpages, or in your own user subpage. The tested changes can be added to this page in a single edit. Please discuss changes on the talk page before implementing them.
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.