diff --git a/core/modules/toolbar/toolbar.module b/core/modules/toolbar/toolbar.module
index c11aaee..7f008b3 100644
--- a/core/modules/toolbar/toolbar.module
+++ b/core/modules/toolbar/toolbar.module
@@ -28,7 +28,7 @@ function toolbar_help($route_name, RouteMatchInterface $route_match) {
       $output .= '<dt>' . t('Tabs') . '</dt>';
       $output .= '<dd>' . t('Tabs are buttons, displayed in a bar across the top of the screen. Some tabs execute an action (such as starting Edit mode), while other tabs toggle which tray is open.') . '</dd>';
       $output .= '<dt>' . t('Trays') . '</dt>';
-      $output .= '<dd>' . t('Trays are usually lists of links, which can be hierarchical like a menu. If a tray has been toggled open, it is displayed either vertically or horizontally below the tab bar, depending on the browser width. In wide browser widths, the user has the ability to toggle from vertical to horizontal, using a link at the bottom or right of the tray. Hierarchical menus only have open/close behavior in vertical mode; if you display a tray containing a hierarchical menu horizontally, only the top-level links will be available.') . '</dd>';
+      $output .= '<dd>' . t('Trays are usually lists of links, which can be hierarchical like a menu. If a tray has been toggled open, it is displayed either vertically or horizontally below the tab bar, depending on the browser width. Only one tray may be open at a time. If you click another tab, that tray will replace the tray being displayed. In wide browser widths, the user has the ability to toggle from vertical to horizontal, using a link at the bottom or right of the tray. Hierarchical menus only have open/close behavior in vertical mode; if you display a tray containing a hierarchical menu horizontally, only the top-level links will be available.') . '</dd>';
       $output .= '</dl>';
       return $output;
   }