diff --git a/Lib/http/__init__.py b/Lib/http/__init__.py
--- a/Lib/http/__init__.py
+++ b/Lib/http/__init__.py
@@ -15,6 +15,7 @@
         * RFC 7238: Permanent Redirect
         * RFC 2295: Transparent Content Negotiation in HTTP
         * RFC 2774: An HTTP Extension Framework
+        * RFC 7225: Status Code to Report Legal Obstacles
     """
     def __new__(cls, value, phrase, description=''):
         obj = int.__new__(cls, value)
@@ -111,6 +112,9 @@
         'Request Header Fields Too Large',
         'The server is unwilling to process the request because its header '
         'fields are too large')
+    UNAVAILABLE_FOR_LEGAL_REASONS = (451, 'Unavailable For Legal Reasons',
+        'The server is denying access to the '
+        'resource as a consequence of a legal demand')
 
     # server errors
     INTERNAL_SERVER_ERROR = (500, 'Internal Server Error',