diff --git a/debian/README b/debian/README
index f8dce19bf..db3125849 100644
--- a/debian/README
+++ b/debian/README
@@ -183,4 +183,19 @@ image_prefix
 
   image_prefix_flavours := sparc32 sparc32-smp
   image_prefix          := sparc32
-  
+
+default_config
+
+  This variable controls which kernel config file will be used as a
+  "default" config file, used when building the kernel-headers package.
+  It does not really matter which file is used, see the message at
+
+  http://lists.debian.org/debian-kernel/2004/08/msg01460.html
+
+  The following algorithm will be used to determine the default kernel
+  config file:
+
+  * If the default_config variable is defined, use config.$(default_config).
+  * If it is not defined and config.default exists, use that.
+  * If neither default_config is defined not config.default exists, pick
+    the first flavour from the flavour list and use its config.