--- a/Resources/CMake/OrthancFrameworkConfiguration.cmake	Wed Aug 30 12:29:48 2017 +0200
+++ b/Resources/CMake/OrthancFrameworkConfiguration.cmake	Wed Aug 30 13:11:37 2017 +0200
@@ -116,7 +116,7 @@
       include(${CMAKE_CURRENT_LIST_DIR}/LibP11Configuration.cmake)
 
       add_definitions(-DORTHANC_ENABLE_PKCS11=1)
-      list(APPEND ORTHANC_CORE_SOURCES
+      list(APPEND ORTHANC_CORE_SOURCES_INTERNAL
         ${ORTHANC_ROOT}/Core/Pkcs11.cpp
         )
     else()
@@ -400,6 +400,14 @@
 ## Gathering of all the source code
 #####################################################################
 
+# The "xxx_INTERNAL" variables list the source code that belongs to
+# the Orthanc project. It can be used to configure precompiled headers
+# if using Microsoft Visual Studio.
+
+# The "xxx_DEPENDENCIES" variables list the source code coming from
+# third-party dependencies.
+
+
 set(ORTHANC_CORE_SOURCES_DEPENDENCIES
   ${BOOST_SOURCES}
   ${CIVETWEB_SOURCES}