The usual...
diff --git a/Lib/dos-8x3/macurl2p.py b/Lib/dos-8x3/macurl2p.py
index 65afe69..7d53d62 100755
--- a/Lib/dos-8x3/macurl2p.py
+++ b/Lib/dos-8x3/macurl2p.py
@@ -1,4 +1,5 @@
-"""Mac specific module for conversion between pathnames and URLs."""
+"""Mac specific module for conversion between pathnames and URLs.
+Do not import directly, use urllib instead."""
 
 import string
 import urllib