Board Thread:Support Requests - Getting Technical/@comment-32704847-20191015045248

Why some white-listed system messages like Editor-template-list, that appear listed here, do not show up when searching them on Special:Allmessages?

Test search on Community Central: [https:/index.php?title=Special:AllMessages&prefix=Editor&filter=all Special:AllMessages&prefix=Editor&filter=all]

I've modified it on a wiki, but it does not show up when I filter by customisation state as "Modified".

Is this related to our MediaWiki version being so outdated? 