diff --git a/src/helpers.cpp b/src/helpers.cpp
index 9657a6d6f..8c0d281c1 100644
--- a/src/helpers.cpp
+++ b/src/helpers.cpp
@@ -222,139 +222,3 @@ static void countTasks (
 }
 
 ////////////////////////////////////////////////////////////////////////////////
-int deltaAppend (Task& task)
-{
-/*
-  if (context.task.has ("description"))
-  {
-    task.set ("description",
-              task.get ("description") + " " + context.task.get ("description"));
-    return 1;
-  }
-*/
-  return 0;
-}
-
-////////////////////////////////////////////////////////////////////////////////
-int deltaPrepend (Task& task)
-{
-/*
-  if (context.task.has ("description"))
-  {
-    task.set ("description",
-              context.task.get ("description") + " " + task.get ("description"));
-    return 1;
-  }
-*/
-
-  return 0;
-}
-
-////////////////////////////////////////////////////////////////////////////////
-int deltaDescription (Task& task)
-{
-/*
-  if (context.task.has ("description"))
-  {
-    task.set ("description", context.task.get ("description"));
-    return 1;
-  }
-*/
-
-  return 0;
-}
-
-////////////////////////////////////////////////////////////////////////////////
-int deltaTags (Task& task)
-{
-  int changes = 0;
-
-/*
-  // Apply or remove tags, if any.
-  std::vector <std::string> tags;
-  context.task.getTags (tags);
-  std::vector <std::string>::iterator tag;
-  for (tag = tags.begin (); tag != tags.end (); ++tag)
-  {
-    task.addTag (*tag);
-    ++changes;
-  }
-
-  for (tag = context.tagRemovals.begin (); tag != context.tagRemovals.end (); ++tag)
-  {
-    task.removeTag (*tag);
-    ++changes;
-  }
-*/
-
-  return changes;
-}
-
-////////////////////////////////////////////////////////////////////////////////
-int deltaAttributes (Task& task)
-{
-  int changes = 0;
-
-/*
-  std::map <std::string, Att>::iterator att;
-  for (att = context.task.begin (); att != context.task.end (); ++att)
-  {
-    if (att->second.name () != "uuid"        &&
-        att->second.name () != "description" &&
-        att->second.name () != "tags")
-    {
-      // Some things don't propagate to the parent task.
-      if (att->second.name () == "wait" &&
-          task.getStatus () == Task::recurring)
-      {
-        // NOP
-      }
-
-      // Modifying "wait" changes status, but not for recurring parent tasks.
-      else if (att->second.name () == "wait")
-      {
-        if (att->second.value () == "")
-        {
-          task.remove (att->first);
-          task.setStatus (Task::pending);
-        }
-        else
-        {
-          task.set (att->first, att->second.value ());
-          task.setStatus (Task::waiting);
-        }
-      }
-
-      // Modifying dependencies requires adding/removing uuids.
-      else if (att->second.name () == "depends")
-      {
-        std::vector <std::string> deps;
-        split (deps, att->second.value (), ',');
-
-        std::vector <std::string>::iterator i;
-        for (i = deps.begin (); i != deps.end (); i++)
-        {
-          int id = atoi (i->c_str ());
-          if (id < 0)
-            task.removeDependency (-id);
-          else
-            task.addDependency (id);
-        }
-      }
-
-      // Now the generalized handling.
-      else if (att->second.value () == "")
-        task.remove (att->second.name ());
-      else
-        // One of the few places where the compound attribute name is used.
-        task.set (att->first, att->second.value ());
-
-      ++changes;
-    }
-  }
-*/
-
-  return changes;
-}
-
-////////////////////////////////////////////////////////////////////////////////
diff --git a/src/main.h b/src/main.h
index 52d96b3c3..cdcfaaf29 100644
--- a/src/main.h
+++ b/src/main.h
@@ -50,11 +50,6 @@ std::string getFullDescription (Task&, const std::string&);
 std::string getDueDate (Task&, const std::string&);
 std::string onProjectChange (Task&, bool scope = true);
 std::string onProjectChange (Task&, Task&);
-int deltaAppend (Task&);
-int deltaPrepend (Task&);
-int deltaDescription (Task&);
-int deltaTags (Task&);
-int deltaAttributes (Task&);
 
 // rules.cpp
 void initializeColorRules ();