diff --git a/Code/Mantid/Framework/TestHelpers/inc/MantidTestHelpers/BinaryOperationMDTestHelper.h b/Code/Mantid/Framework/TestHelpers/inc/MantidTestHelpers/BinaryOperationMDTestHelper.h
index c01af41235bd..557f2333a4d1 100644
--- a/Code/Mantid/Framework/TestHelpers/inc/MantidTestHelpers/BinaryOperationMDTestHelper.h
+++ b/Code/Mantid/Framework/TestHelpers/inc/MantidTestHelpers/BinaryOperationMDTestHelper.h
@@ -1,3 +1,8 @@
+/*********************************************************************************
+ *  PLEASE READ THIS!!!!!!!
+ *
+ *  This header MAY ONLY be included from a test in the MDAlgorithms package.
+ *********************************************************************************/
 #ifndef MANTID_MDALGORITHMS_BINARYOPERATIONMDTESTHELPER_H_
 #define MANTID_MDALGORITHMS_BINARYOPERATIONMDTESTHELPER_H_
 
diff --git a/Code/Mantid/Framework/TestHelpers/inc/MantidTestHelpers/BoxControllerDummyIO.h b/Code/Mantid/Framework/TestHelpers/inc/MantidTestHelpers/BoxControllerDummyIO.h
index b875fdb4fc06..807afb0c2814 100644
--- a/Code/Mantid/Framework/TestHelpers/inc/MantidTestHelpers/BoxControllerDummyIO.h
+++ b/Code/Mantid/Framework/TestHelpers/inc/MantidTestHelpers/BoxControllerDummyIO.h
@@ -1,3 +1,11 @@
+/*********************************************************************************
+ *  PLEASE READ THIS!!!!!!!
+ *
+ *  This header MAY NOT be included in any test from a package below API
+ *    (e.g. Kernel, Geometry).
+ *  Conversely, this file MAY NOT be modified to use anything from a package higher
+ *  than API (e.g. any algorithm or concrete workspace), even if via the factory.
+ *********************************************************************************/
 #ifndef MANTID_TESTHELPERS_BOXCONTROLLER_DUMMUY_IO_H
 #define MANTID_TESTHELPERS_BOXCONTROLLER_DUMMUY_IO_H
 
@@ -100,4 +108,4 @@ namespace MantidTestHelpers
     };
 
 }
-#endif
\ No newline at end of file
+#endif
diff --git a/Code/Mantid/Framework/TestHelpers/inc/MantidTestHelpers/ComponentCreationHelper.h b/Code/Mantid/Framework/TestHelpers/inc/MantidTestHelpers/ComponentCreationHelper.h
index 95899c8e0f4a..1fc15c83b136 100644
--- a/Code/Mantid/Framework/TestHelpers/inc/MantidTestHelpers/ComponentCreationHelper.h
+++ b/Code/Mantid/Framework/TestHelpers/inc/MantidTestHelpers/ComponentCreationHelper.h
@@ -1,3 +1,11 @@
+/*********************************************************************************
+ *  PLEASE READ THIS!!!!!!!
+ *
+ *  This header MAY NOT be included in any test from a package below Geometry
+ *    (e.g. Kernel).
+ *  Conversely, this file (and its cpp) MAY NOT be modified to use anything from a
+ *  package higher than Geometry (e.g. API, DataObjects, ...)
+ *********************************************************************************/
 #ifndef COMPONENTCREATIONHELPER_H_
 #define COMPONENTCREATIONHELPER_H_
 
diff --git a/Code/Mantid/Framework/TestHelpers/inc/MantidTestHelpers/FacilityHelper.h b/Code/Mantid/Framework/TestHelpers/inc/MantidTestHelpers/FacilityHelper.h
index 3b1f10ab5f70..b045f0705794 100644
--- a/Code/Mantid/Framework/TestHelpers/inc/MantidTestHelpers/FacilityHelper.h
+++ b/Code/Mantid/Framework/TestHelpers/inc/MantidTestHelpers/FacilityHelper.h
@@ -1,3 +1,8 @@
+/*********************************************************************************
+ *  PLEASE READ THIS!!!!!!!
+ *
+ *  This file MAY NOT be modified to use anything from a package other than Kernel.
+ *********************************************************************************/
 #ifndef TESTHELPERS_FACILITYHELPER_H_
 #define TESTHELPERS_FACILITYHELPER_H_
 
diff --git a/Code/Mantid/Framework/TestHelpers/inc/MantidTestHelpers/FakeGmockObjects.h b/Code/Mantid/Framework/TestHelpers/inc/MantidTestHelpers/FakeGmockObjects.h
index 3df1144d4452..51ae312a5f58 100644
--- a/Code/Mantid/Framework/TestHelpers/inc/MantidTestHelpers/FakeGmockObjects.h
+++ b/Code/Mantid/Framework/TestHelpers/inc/MantidTestHelpers/FakeGmockObjects.h
@@ -1,27 +1,17 @@
+/*********************************************************************************
+ *  PLEASE READ THIS!!!!!!!
+ *
+ *  This header MAY NOT be included in any test from a package below Geometry
+ *    (i.e. Kernel).
+ *  Conversely, this file MAY NOT be modified to use anything from a package higher
+ *  than API (e.g. any algorithm or concrete workspace), even if via the factory.
+ *********************************************************************************/
 #ifndef FAKEGMOCKOBJECTS_H_
 #define FAKEGMOCKOBJECTS_H_
 
-/*
- * FakeObjects.h: Fake Tester objects for APITest
- *
- *  Created on: Jul 5, 2011
- *      Author: Janik Zikovsky
- */
-
-#include "MantidAPI/ISpectrum.h"
-#include "MantidAPI/MatrixWorkspace.h"
-#include "MantidKernel/cow_ptr.h"
-#include "MantidAPI/NumericAxis.h"
-#include "MantidGeometry/Instrument.h"
-#include "MantidGeometry/Instrument/DetectorGroup.h"
 #include "MantidGeometry/Instrument/INearestNeighboursFactory.h"
 #include "gmock/gmock.h"
-#include <iostream>
-#include <fstream>
-#include <map>
 
-using namespace Mantid::API;
-using namespace Mantid::Kernel;
 using namespace Mantid;
 
 
diff --git a/Code/Mantid/Framework/TestHelpers/inc/MantidTestHelpers/FakeObjects.h b/Code/Mantid/Framework/TestHelpers/inc/MantidTestHelpers/FakeObjects.h
index 6256d8d631d9..e02d19f6a907 100644
--- a/Code/Mantid/Framework/TestHelpers/inc/MantidTestHelpers/FakeObjects.h
+++ b/Code/Mantid/Framework/TestHelpers/inc/MantidTestHelpers/FakeObjects.h
@@ -1,3 +1,11 @@
+/*********************************************************************************
+ *  PLEASE READ THIS!!!!!!!
+ *
+ *  This header MAY NOT be included in any test from a package below API
+ *    (e.g. Kernel, Geometry).
+ *  Conversely, this file MAY NOT be modified to use anything from a package higher
+ *  than API (e.g. any algorithm or concrete workspace), even if via the factory.
+ *********************************************************************************/
 #ifndef FAKEOBJECTS_H_
 #define FAKEOBJECTS_H_
 
diff --git a/Code/Mantid/Framework/TestHelpers/inc/MantidTestHelpers/MDEventsTestHelper.h b/Code/Mantid/Framework/TestHelpers/inc/MantidTestHelpers/MDEventsTestHelper.h
index 452442908dea..1bcc78816a8e 100644
--- a/Code/Mantid/Framework/TestHelpers/inc/MantidTestHelpers/MDEventsTestHelper.h
+++ b/Code/Mantid/Framework/TestHelpers/inc/MantidTestHelpers/MDEventsTestHelper.h
@@ -1,3 +1,9 @@
+/*********************************************************************************
+ *  PLEASE READ THIS!!!!!!!
+ *
+ *  This header MAY NOT be included in any test from a package below the level of
+ *  MDEvents (e.g. Kernel, Geometry, API, DataObjects).
+ *********************************************************************************/
 #ifndef MDEVENTSTEST_HELPER_H
 #define MDEVENTSTEST_HELPER_H
 
diff --git a/Code/Mantid/Framework/TestHelpers/inc/MantidTestHelpers/SANSInstrumentCreationHelper.h b/Code/Mantid/Framework/TestHelpers/inc/MantidTestHelpers/SANSInstrumentCreationHelper.h
index 2535744a96f7..09d78f68c791 100644
--- a/Code/Mantid/Framework/TestHelpers/inc/MantidTestHelpers/SANSInstrumentCreationHelper.h
+++ b/Code/Mantid/Framework/TestHelpers/inc/MantidTestHelpers/SANSInstrumentCreationHelper.h
@@ -1,3 +1,10 @@
+/*********************************************************************************
+ *  PLEASE READ THIS!!!!!!!
+ *
+ *  This header MAY NOT be included in any test from a package below the level of
+ *  DataHandling (e.g. Kernel, Geometry, API, DataObjects).
+ *  I.e. It can only be used by plugin/algorithm-level packages (e.g. DataHandling)
+ *********************************************************************************/
 #ifndef SANSINSTRUMENTCREATIONHELPER_H_
 #define SANSINSTRUMENTCREATIONHELPER_H_
 
diff --git a/Code/Mantid/Framework/TestHelpers/inc/MantidTestHelpers/WorkspaceCreationHelper.h b/Code/Mantid/Framework/TestHelpers/inc/MantidTestHelpers/WorkspaceCreationHelper.h
index 617f7219e92f..d59aee9ed81d 100644
--- a/Code/Mantid/Framework/TestHelpers/inc/MantidTestHelpers/WorkspaceCreationHelper.h
+++ b/Code/Mantid/Framework/TestHelpers/inc/MantidTestHelpers/WorkspaceCreationHelper.h
@@ -1,3 +1,11 @@
+/*********************************************************************************
+ *  PLEASE READ THIS!!!!!!!
+ *
+ *  This header MAY NOT be included in any test from a package below DataObjects
+ *    (e.g. Kernel, Geometry, API).
+ *  Conversely, this file (and its cpp) MAY NOT be modified to use anything from a
+ *  package higher than DataObjects (e.g. any algorithm), even if via the factory.
+ *********************************************************************************/
 #ifndef WORKSPACECREATIONHELPER_H_
 #define WORKSPACECREATIONHELPER_H_
 //------------------------------------------------------------------------------
diff --git a/Code/Mantid/Framework/TestHelpers/src/BinaryOperationMDTestHelper.cpp b/Code/Mantid/Framework/TestHelpers/src/BinaryOperationMDTestHelper.cpp
index 04e432409af7..d2cf38738342 100644
--- a/Code/Mantid/Framework/TestHelpers/src/BinaryOperationMDTestHelper.cpp
+++ b/Code/Mantid/Framework/TestHelpers/src/BinaryOperationMDTestHelper.cpp
@@ -1,4 +1,8 @@
-
+/*********************************************************************************
+ *  PLEASE READ THIS!!!!!!!
+ *
+ *  These functions MAY ONLY be used in a test in the MDAlgorithms package.
+ *********************************************************************************/
 #include "MantidAPI/IMDEventWorkspace.h"
 #include "MantidDataObjects/WorkspaceSingleValue.h"
 #include "MantidKernel/System.h"
diff --git a/Code/Mantid/Framework/TestHelpers/src/BoxControllerDummyIO.cpp b/Code/Mantid/Framework/TestHelpers/src/BoxControllerDummyIO.cpp
index 2a0e1def4b53..cc1338351e7e 100644
--- a/Code/Mantid/Framework/TestHelpers/src/BoxControllerDummyIO.cpp
+++ b/Code/Mantid/Framework/TestHelpers/src/BoxControllerDummyIO.cpp
@@ -1,3 +1,11 @@
+/*********************************************************************************
+ *  PLEASE READ THIS!!!!!!!
+ *
+ *  This collection of functions MAY NOT be used in any test from a package below
+ *  API (e.g. Kernel, Geometry).
+ *  Conversely, this file MAY NOT be modified to use anything from a package higher
+ *  than API (e.g. any algorithm or concrete workspace), even if via the factory.
+ *********************************************************************************/
 #include "MantidTestHelpers/BoxControllerDummyIO.h"
 #include "MantidKernel/Exception.h"
 
@@ -160,4 +168,4 @@ namespace MantidTestHelpers
       this->closeFile();
   }
 
-}
\ No newline at end of file
+}
diff --git a/Code/Mantid/Framework/TestHelpers/src/ComponentCreationHelper.cpp b/Code/Mantid/Framework/TestHelpers/src/ComponentCreationHelper.cpp
index 2f3ffe434123..1aa49e33f19e 100644
--- a/Code/Mantid/Framework/TestHelpers/src/ComponentCreationHelper.cpp
+++ b/Code/Mantid/Framework/TestHelpers/src/ComponentCreationHelper.cpp
@@ -1,3 +1,11 @@
+/*********************************************************************************
+ *  PLEASE READ THIS!!!!!!!
+ *
+ *  This collection of functions MAY NOT be used in any test from a package below
+ *  Geometry (e.g. Kernel).
+ *  Conversely, this file MAY NOT be modified to use anything from a package
+ *  higher than Geometry (e.g. API, DataObjects, ...)
+ *********************************************************************************/
 //------------------------------------------------------------------------------
 // Includes
 //------------------------------------------------------------------------------
diff --git a/Code/Mantid/Framework/TestHelpers/src/MDEventsTestHelper.cpp b/Code/Mantid/Framework/TestHelpers/src/MDEventsTestHelper.cpp
index d8d125c8730d..a5bd06924e35 100644
--- a/Code/Mantid/Framework/TestHelpers/src/MDEventsTestHelper.cpp
+++ b/Code/Mantid/Framework/TestHelpers/src/MDEventsTestHelper.cpp
@@ -1,3 +1,10 @@
+/*********************************************************************************
+ *  PLEASE READ THIS!!!!!!!
+ *
+ *  This collection of functions MAY NOT be used in any test from a package below
+ *  the level of MDEvents (e.g. Kernel, Geometry, API, DataObjects).
+ *********************************************************************************/
+
 #include "MantidAPI/MatrixWorkspace.h"
 #include "MantidDataHandling/LoadInstrument.h"
 #include "MantidDataObjects/EventWorkspace.h"
diff --git a/Code/Mantid/Framework/TestHelpers/src/SANSInstrumentCreationHelper.cpp b/Code/Mantid/Framework/TestHelpers/src/SANSInstrumentCreationHelper.cpp
index 542ca61aca54..bae68c4ccd49 100644
--- a/Code/Mantid/Framework/TestHelpers/src/SANSInstrumentCreationHelper.cpp
+++ b/Code/Mantid/Framework/TestHelpers/src/SANSInstrumentCreationHelper.cpp
@@ -1,3 +1,10 @@
+/*********************************************************************************
+ *  PLEASE READ THIS!!!!!!!
+ *
+ *  This collection of functions MAY NOT be used in any test from a package below
+ *  the level of DataHandling (e.g. Kernel, Geometry, API, DataObjects).
+ *  I.e. It can only be used by plugin/algorithm-level packages (e.g. DataHandling)
+ *********************************************************************************/
 #include "MantidTestHelpers/SANSInstrumentCreationHelper.h"
 #include "MantidTestHelpers/WorkspaceCreationHelper.h"
 #include "MantidAPI/AnalysisDataService.h"
diff --git a/Code/Mantid/Framework/TestHelpers/src/WorkspaceCreationHelper.cpp b/Code/Mantid/Framework/TestHelpers/src/WorkspaceCreationHelper.cpp
index afe11e5e2fec..0639a060a5a3 100644
--- a/Code/Mantid/Framework/TestHelpers/src/WorkspaceCreationHelper.cpp
+++ b/Code/Mantid/Framework/TestHelpers/src/WorkspaceCreationHelper.cpp
@@ -1,3 +1,11 @@
+/*********************************************************************************
+ *  PLEASE READ THIS!!!!!!!
+ *
+ *  This collection of functions MAY NOT be used in any test from a package below
+ *  DataObjects (e.g. Kernel, Geometry, API).
+ *  Conversely, this file MAY NOT be modified to use anything from a package higher
+ *  than DataObjects (e.g. any algorithm), even if going via the factory.
+ *********************************************************************************/
 //------------------------------------------------------------------------------
 // Includes
 //------------------------------------------------------------------------------