In my previous post, "multiple wikis, single MediaWiki file tree", I
demonstrated my sparkling single LocalSettings.php, AdminSettings.php,
and indeed entire MediaWiki file tree, for multiple wikis right there
on the same server.
Platonides (P) responded with a more aggressive approach that rips up
more of LocalSettings.php than I (D) dare. And in closing, he says
D> $wgDBserver="mysql.$wgServerName";
P> I suppose you know what will be happening if someone finds a way to
P> overwrite your $wgServerName variable...
How could that happen? $wgServerName is born in the safe confines of
DefaultSettings.php.