Manual:$wgLogActions

Details
Lists the message key string for formatting individual events of each type and action when listed in the logs. Extensions with custom log types may add to this array. Same as $wgLogActionsHandlers but without function callbacks as values.

See Manual:Logging to Special:Log for more information about logging in MediaWiki.

Default value
The comment after each item indicates the version of MediaWiki in which it was introduced.