Index: modules/block/block.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/block/block.module,v
retrieving revision 1.243
diff -u -p -r1.243 block.module
--- modules/block/block.module	10 Dec 2006 09:54:33 -0000	1.243
+++ modules/block/block.module	11 Dec 2006 09:15:50 -0000
@@ -6,6 +6,10 @@
  * Controls the boxes that are displayed around the main content.
  */
 
+/**
+ * Denotes that a block is not enabled in any region and should not
+ * be shown.
+ */
 define('BLOCK_REGION_NONE', -1);
 
 /**