diff -r b1b898c00b71 -r cb9493a80341 src/share/classes/com/sun/tools/javac/main/RecognizedOptions.java
--- a/src/share/classes/com/sun/tools/javac/main/RecognizedOptions.java	Mon Mar 07 11:37:54 2011 -0800
+++ b/src/share/classes/com/sun/tools/javac/main/RecognizedOptions.java	Mon Mar 07 13:45:06 2011 -0800
@@ -168,6 +168,7 @@
         O,
         XJCOV,
         XD,
+        AT,
         SOURCEFILE);
 
     static Set<OptionName> javacFileManagerOptions = EnumSet.of(
@@ -565,12 +566,27 @@
             }
         },
 
+        // This option exists only for the purpose of documenting itself.
+        // It's actually implemented by the CommandLine class.
+        new Option(AT,                   "opt.arg.file",         "opt.AT") {
+            @Override
+            String helpSynopsis() {
+                hasSuffix = true;
+                return super.helpSynopsis();
+            }
+            @Override
+            public boolean process(Options options, String option) {
+                throw new AssertionError
+                    ("the @ flag should be caught by CommandLine.");
+            }
+        },
+
         /*
          * TODO: With apt, the matches method accepts anything if
          * -XclassAsDecls is used; code elsewhere does the lookup to
          * see if the class name is both legal and found.
          *
-         * In apt, the process method adds the candiate class file
+         * In apt, the process method adds the candidate class file
          * name to a separate list.
          */
         new HiddenOption(SOURCEFILE) {