--- a/src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/toolkit/util/DocletConstants.java	Wed Dec 13 21:25:49 2017 +0100
+++ b/src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/toolkit/util/DocletConstants.java	Wed Dec 13 12:45:06 2017 -0800
@@ -54,6 +54,16 @@
     public static final String DEFAULT_PACKAGE_NAME = "<Unnamed>";
 
     /**
+     * The default module or a package name.
+     */
+    public static final String DEFAULT_ELEMENT_NAME = "<Unnamed>";
+
+    /**
+     * The module prefix in the element-list file.
+     */
+    public static final String MODULE_PREFIX = "module:";
+
+    /**
      * The default package file name.
      */
     public static final String DEFAULT_PACKAGE_FILE_NAME = "default";