The Vietnamese Wikibooks community has reached consensus (permalink) to set the $wgRestrictDisplayTitle setting to false for consistency with the English Wikibooks (which requested the same change in T32808). The votes in favor include every registered user who has been active this month (and probably several months before that).
|operations/mediawiki-config||master||+1 -0||[viwikibooks] Set $wgRestrictDisplayTitle to false|
@lamducanh: If this is urgent and you would like to make this configuration change yourself, then please follow https://wikitech.wikimedia.org/wiki/Wikimedia_site_requests and edit the file InitialiseSettings.php.txt via putting a patch in Gerrit. Thanks.