bookstack/resources/lang/en/activities.php

<?php
/**
 * Activity text strings.
 * Is used for all the text within activity logs & notifications.
 */
return [

    // Pages
    'page_create'                 => 'created page',
    'page_create_notification'    => 'Page Successfully Created',
    'page_update'                 => 'updated page',
    'page_update_notification'    => 'Page Successfully Updated',
    'page_delete'                 => 'deleted page',
    'page_delete_notification'    => 'Page Successfully Deleted',
    'page_restore'                => 'restored page',
    'page_restore_notification'   => 'Page Successfully Restored',
    'page_move'                   => 'moved page',

    // Chapters
    'chapter_create'              => 'created chapter',
    'chapter_create_notification' => 'Chapter Successfully Created',
    'chapter_update'              => 'updated chapter',
    'chapter_update_notification' => 'Chapter Successfully Updated',
    'chapter_delete'              => 'deleted chapter',
    'chapter_delete_notification' => 'Chapter Successfully Deleted',
    'chapter_move'                => 'moved chapter',

    // Books
    'book_create'                 => 'created book',
    'book_create_notification'    => 'Book Successfully Created',
    'book_update'                 => 'updated book',
    'book_update_notification'    => 'Book Successfully Updated',
    'book_delete'                 => 'deleted book',
    'book_delete_notification'    => 'Book Successfully Deleted',
    'book_sort'                   => 'sorted book',
    'book_sort_notification'      => 'Book Successfully Re-sorted',

    // Bookshelves
    'bookshelf_create'            => 'created Bookshelf',
    'bookshelf_create_notification'    => 'Bookshelf Successfully Created',
    'bookshelf_update'                 => 'updated bookshelf',
    'bookshelf_update_notification'    => 'Bookshelf Successfully Updated',
    'bookshelf_delete'                 => 'deleted bookshelf',
    'bookshelf_delete_notification'    => 'Bookshelf Successfully Deleted',

    // Other
    'commented_on'                => 'commented on',
];