&$blacklist: array of checks to blacklist. See the bottom of
maintenance/language/checkLanguage.inc for the format of this variable.
+'LocalisationIgnoredOptionalMessages': When fetching the list of ignored and
+optional localisation messages
+&$ignored Array of ignored message keys
+&$optional Array of optional message keys
+
'LogEventsListShowLogExtract': Called before the string is added to OutputPage.
Returning false will prevent the string from being added to the OutputPage.
&$s: html string to show for the log extract
message must be in HTML format, not wikitext!
&$link: overridable HTML link to be passed into the message as $1
&$forContent: overridable flag if copyright footer is shown in content language.
+ This parameter is deprecated.
'SkinGetPoweredBy': TODO
&$text: additional 'powered by' icons in HTML. Note: Modern skin does not use