diff --git a/index.php b/index.php
index 63769d0..33412f7 100644
--- a/index.php
+++ b/index.php
@@ -36,6 +36,8 @@
     'delete' => ''
 );
 
+$description = '';
+
 // We could be a course or a category.
 switch ($context->contextlevel) {
     case \CONTEXT_COURSE:
@@ -48,6 +50,7 @@
         );
 
         $recyclebin = new \local_recyclebin\course($context->instanceid);
+        $description = get_string('description_course', 'local_recyclebin');
     break;
 
     case \CONTEXT_COURSECAT:
@@ -61,10 +64,11 @@
         );
 
         $recyclebin = new \local_recyclebin\category($context->instanceid);
+        $description = get_string('description_coursecat', 'local_recyclebin');
     break;
 
     default:
-        print_error("Invalid context supplied.");
+        print_error('invalidcontext', 'local_recyclebin');
     break;
 }
 
@@ -131,7 +135,6 @@
 }
 
 // Start with a description.
-$description = get_string('description', 'local_recyclebin');
 $expiry = get_config('local_recyclebin', 'expiry');
 if ($expiry > 0) {
     $description .= ' ' . get_string('descriptionexpiry', 'local_recyclebin', $expiry);
diff --git a/lang/en/local_recyclebin.php b/lang/en/local_recyclebin.php
index f4a2a2c..2f5f11c 100644
--- a/lang/en/local_recyclebin.php
+++ b/lang/en/local_recyclebin.php
@@ -28,7 +28,7 @@
 $string['cleanrecyclebin'] = 'Clean recycle bin';
 
 $string['expiry'] = 'Item lifetime';
-$string['expiry_desc'] = 'How long should a deleted activity remain in the recycle bin?';
+$string['expiry_desc'] = 'How long should a deleted item remain in the recycle bin?';
 
 $string['autohide'] = 'Auto hide?';
 $string['autohide_desc'] = 'Automatically hides the recycle bin link when the bin is empty.';
@@ -57,9 +57,12 @@
 $string['event_restored_description'] = 'Item with ID {$a->objectid} restored.';
 $string['event_purged_description'] = 'Item with ID {$a->objectid} purged.';
 
-$string['description'] = 'Items that have been deleted from a course can be restored and will appear at the bottom of the section from which they were deleted.';
+$string['description_course'] = 'Items that have been deleted from a course can be restored if they are still in the recyclebin, and will appear at the bottom of the section from which they were deleted.';
+$string['description_coursecat'] = 'Items that have been deleted from a category can be restored if they are still in the recyclebin.';
 $string['descriptionexpiry'] = 'Contents will be permanently deleted after {$a} days.';
 
 $string['emptybin'] = 'There are no items in the recycle bin.';
 $string['emptyconfirm'] = 'Are you sure you want to delete all items in the recycle bin?';
-$string['deleteconfirm'] = 'Are you sure you want to delete the selected item in the recycle bin?';
+$string['deleteconfirm'] = 'Are you sure you want to delete the selected item from the recycle bin?';
+
+$string['invalidcontext'] = 'Invalid context supplied.';