Use the BookmarkImage property to specify the icon being displayed when a line is bookmarked. Use the BookmarkWidth property to display the control's bookmarks header bar. Use the Images method to assign a list of icons to the control. Use the ReplaceIcon method to add, remove or replace an icon in the control's images list.  By default, the BookmarkImage property is -1. If the BookmarkImage property is -1, the control displays the default bookmark. Use the BookmarkImageLine property to display an icon on the bookmarks header bar.