Thread:Project:Support desk/Page meta title in newest version 1.19.1/reply (2)

You edit that by modifying the page MediaWiki:Pagetitle and MediaWiki:Pagetitle-view-mainpage (for mainpage) on your wiki. (Note that's the page on your wiki. The links here go to the equivalent pages on this wiki. You need to edit those pages on your wiki). See manual:System messages for details.

Please do not edit php files to change this sort of thing. This will break on upgrade and is not supported.