This is a useful setting to sort the left menu alphabetically in the Administration Interface:

https://github.com/ezsystems/ezpublish-legacy/blob/master/settings/contentstructuremenu.ini#L32

... but if you use that setting with an array and try to view the contentstructuremenu.ini settings in Setup > Ini settings, you get this error:

An unexpected error has occurred. Please contact the webmaster.
[] operator not supported for strings in /var/www/marigold/ezpublish_legacy/lib/ezutils/classes/ezini.php on line 868