What are numbered headings?
MediaWiki does not display heading numbers for individual sections by default. If you want your wiki to use heading numbers, you can enable this in the Configuration Manager.
Configuration
Under "Content structuring", select the checkbox for NumberHeadings.
- Enable heading numbering: Displays the numbering from the table of contents before the section headings on a page.

Number headings 
Activated heading numbers
Adjsut the scope
With this configuration setting enabled, numbered headings will be activated for the entire wiki.
Since this is not always appropriate in some namespaces or on some pages, you can override the setting via MediaWiki:Common.css.
/*Hide heading numbers */
.ns-3020 .mw-headline-number, /*Hide in namespace 3020 (find ID via namespace management)*/
.ns-3004 .mw-headline-number,
.ns-3006 .mw-headline-number,
.ns-3008 .mw-headline-number,
.ns-3010 .mw-headline-number,
.page-Terminology .mw-headline-number /*Hide on page "Terminology" (find page name via source code)*/
{
display:none
}
Page source code via browser context menu] open
Important!
Note possible overlap with the Chapter numbering of page sections in books.