diff --git a/CODE.rst b/CODE.rst
index 10d90337653ab0088402d4f58efe65c8cded0a48..75327523374bf9a99b05900b4e0185ee155b3bee 100644
--- a/CODE.rst
+++ b/CODE.rst
@@ -51,7 +51,13 @@ Hooks make arbitrary transformations to entry data dicts.  Every entry data dict
   Initializes the hook with the user's configuration.
 
 ``run(entry_data)``
-  This method makes the hook's transformations to the entry data dict, if any.  If this method sets ``entry_data['_hook_cancel']`` to a truthy value, that entry will not be output.
+  This method can make arbitrary transformations to the entry data, or filter it so it isn't output.
+
+  If this method returns ``None``, processing the entry data continues normally.  Most hooks should do this, and just transform entry data in place.
+
+  If this method returns ``False``, processing the entry data stops immediately.  The entry will not appear in the program output.
+
+  If this method returns any other value, the program replaces the entry data with the return value, and continues processing.
 
 Templates
 ~~~~~~~~~
@@ -86,9 +92,14 @@ At a high level, import2ledger handles each input file this way::
     input_file.seek(0)
     for entry_data in importer_class(input_file):
       for hook in all_hooks:
-        hook.run(entry_data)
-      if entry_data:
-        template.render(entry_data)
+        hook_return = hook.run(entry_data)
+        if hook_return is False:
+          break
+        elif hook_return is not None:
+          entry_data = hook_return
+      else:
+        if entry_data:
+          template.render(entry_data)
 
 Note in particular that multiple importers can handle the same input file.  This helps support inputs like Patreon's earnings CSV, where completely different transactions are generated from the same source.