Bookmark icon class - Set the class for the bookmark icon here if you'd like to use a different font set or a different FontAwesome icon.
Bookmark icon class (bookmarked) - This is the icon that will be displayed on content that has already been bookmarked.
Sticky icon class - This is the icon that will be used to indicate a sticky bookmark.
Public icon class - This is the icon that will be used to indicate a public bookmark.
Be sure that when using FontAwesome icons that you use fa fa-book instead of fa-book.