BookStack/resources/lang/de_informal/activities.php

<?php
$de_formal = (include resource_path() . '/lang/de/' . basename(__FILE__));

$de_informal = [

    /**
     * Activity text strings.
     * Is used for all the text within activity logs & notifications.
     */

    // Pages
 
    // Chapters
   
    // Books
    
    // Bookshelves
    
    // Other
    
];

return array_replace($de_formal, $de_informal);