Namespace tab.
I need to understand the term Nstab to ensure I work with MediaWiki:Mainpage-nstab system message correctly.
What is an Nstab in MediaWiki terminology?
This question is a follow up for the question Changing homepage name to site name per $wgSitename value.
Some example of the term in the context of MediaWiki would be helpful.
On the standard Vector skin there are two main tabs, one for the page and one for the related talk page. I guess their names vary per namespace and this is how you set the relevant values.
The tab in the upper left corner of this (desktop) page is labeled “Topic” in English but “Thema” in German as controlled via MediaWiki:nstab-topic (imported from upstream) and “Wątek” in Polish via local MediaWiki:nstab-topic/pl. Well, if you visit the particular thread.
The main namespace, the focus of interest with ns=0, is called “Gallery” on commons:Earth but “Article” on w:en:Earth (English Wikipedia) and “Item” on d:Q2 (Wikidata). Defined via MediaWiki:nstab-main or inherited from upstream (“Page”).
So I understand that Nstab is the tab which would generally be "main page" (for main pages only) or "article" (for article pages only), "topic" (for topic pages here in the MediaWiki community website), etc. and is pretty much only the uppermost-leftmost tab in MediaWiki websites.
