diff -rupN apachesolr_attachments/README.txt apachesolr_attachments_new/README.txt
--- apachesolr_attachments/README.txt	2009-10-22 04:53:42.000000000 +1100
+++ README.txt	2009-12-18 10:36:44.245791522 +1100
@@ -39,3 +39,22 @@ in a location like ~/.m2/repository/org/
 Copy tika-app-0.4.jar from there or point the module path to it.
 
 See also build instructions at: http://drupal.org/node/540974#comment-1944082
+
+
+Developers
+--------------
+
+Exposed Hooks in 6.x:
+
+hook_apachesolr_attachment_index_alter(&$document, $node, $file)
+
+  Allows a module to change the contents of the attachment $document object before it is sent to the Solr Server.
+  To add a new field to the document, you should generally use one of the pre-defined dynamic fields. 
+  Follow the naming conventions for the type of data being added based on the apachesolr schema.xml file.
+
+  NOTE: If you have a module that already implements hook_apachesolr_update_index and you want the same index
+        changes for attachments you can do this:
+
+        function my_module_apachesolr_attachment_index_alter(&$document, $node, $file) {
+          my_module_apachesolr_update_index($document, $node);
+        }