It often happens that wiki sysops want to change it site wide, especially when they want to change the format (eg, have {{SITENAME}} removed, or replace the hyphen with a middot).
There's [[mw:manual:$wgForceUIMsgAsContentMsg]] available for anyone who have another need anyway.
Version: unspecified
Severity: normal
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=44492