diff --git a/test/vs2017/etl.vcxproj b/test/vs2017/etl.vcxproj
index 331a6f54..d08e0d24 100644
--- a/test/vs2017/etl.vcxproj
+++ b/test/vs2017/etl.vcxproj
@@ -904,6 +904,7 @@
     <Text Include="..\..\CMakeLists.txt" />
     <Text Include="..\..\include\etl\file_error_numbers.txt" />
     <Text Include="..\..\support\Release notes.txt" />
+    <Text Include="..\..\todo.txt" />
     <Text Include="..\CMakeLists.txt" />
   </ItemGroup>
   <ItemGroup>
diff --git a/test/vs2017/etl.vcxproj.filters b/test/vs2017/etl.vcxproj.filters
index 856baf1d..9d6f1f88 100644
--- a/test/vs2017/etl.vcxproj.filters
+++ b/test/vs2017/etl.vcxproj.filters
@@ -79,6 +79,9 @@
     <Filter Include="ETL\STL\Alternate">
       <UniqueIdentifier>{0d093ee6-686c-4c9e-856e-bdf7075ff7a6}</UniqueIdentifier>
     </Filter>
+    <Filter Include="ETL\Strings">
+      <UniqueIdentifier>{da88d71d-e5ea-4c26-9807-94616d31addb}</UniqueIdentifier>
+    </Filter>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="..\..\include\etl\enum_type.h">
@@ -297,18 +300,6 @@
     <ClInclude Include="..\..\include\etl\platform.h">
       <Filter>ETL\Utilities</Filter>
     </ClInclude>
-    <ClInclude Include="..\..\include\etl\basic_string.h">
-      <Filter>ETL\Containers</Filter>
-    </ClInclude>
-    <ClInclude Include="..\..\include\etl\u16string.h">
-      <Filter>ETL\Containers</Filter>
-    </ClInclude>
-    <ClInclude Include="..\..\include\etl\u32string.h">
-      <Filter>ETL\Containers</Filter>
-    </ClInclude>
-    <ClInclude Include="..\..\include\etl\wstring.h">
-      <Filter>ETL\Containers</Filter>
-    </ClInclude>
     <ClInclude Include="..\..\include\etl\private\pvoidvector.h">
       <Filter>ETL\Private</Filter>
     </ClInclude>
@@ -324,9 +315,6 @@
     <ClInclude Include="..\..\include\etl\intrusive_queue.h">
       <Filter>ETL\Containers</Filter>
     </ClInclude>
-    <ClInclude Include="..\..\include\etl\cstring.h">
-      <Filter>ETL\Containers</Filter>
-    </ClInclude>
     <ClInclude Include="..\..\include\etl\unordered_multimap.h">
       <Filter>ETL\Containers</Filter>
     </ClInclude>
@@ -474,9 +462,6 @@
     <ClInclude Include="..\..\include\etl\array_view.h">
       <Filter>ETL\Containers</Filter>
     </ClInclude>
-    <ClInclude Include="..\..\include\etl\string_view.h">
-      <Filter>ETL\Containers</Filter>
-    </ClInclude>
     <ClInclude Include="..\..\include\etl\array_wrapper.h">
       <Filter>ETL\Containers</Filter>
     </ClInclude>
@@ -732,39 +717,12 @@
     <ClInclude Include="..\..\include\etl\queue_spsc_locked.h">
       <Filter>ETL\Containers</Filter>
     </ClInclude>
-    <ClInclude Include="..\..\include\etl\to_string.h">
-      <Filter>ETL\Utilities</Filter>
-    </ClInclude>
     <ClInclude Include="..\..\include\etl\negative.h">
       <Filter>ETL\Utilities</Filter>
     </ClInclude>
-    <ClInclude Include="..\..\include\etl\format_spec.h">
-      <Filter>ETL\Utilities</Filter>
-    </ClInclude>
-    <ClInclude Include="..\..\include\etl\to_u16string.h">
-      <Filter>ETL\Utilities</Filter>
-    </ClInclude>
-    <ClInclude Include="..\..\include\etl\to_u32string.h">
-      <Filter>ETL\Utilities</Filter>
-    </ClInclude>
-    <ClInclude Include="..\..\include\etl\to_wstring.h">
-      <Filter>ETL\Utilities</Filter>
-    </ClInclude>
     <ClInclude Include="..\..\include\etl\private\to_string_helper.h">
       <Filter>ETL\Private</Filter>
     </ClInclude>
-    <ClInclude Include="..\..\include\etl\basic_format_spec.h">
-      <Filter>ETL\Utilities</Filter>
-    </ClInclude>
-    <ClInclude Include="..\..\include\etl\u16format_spec.h">
-      <Filter>ETL\Utilities</Filter>
-    </ClInclude>
-    <ClInclude Include="..\..\include\etl\u32format_spec.h">
-      <Filter>ETL\Utilities</Filter>
-    </ClInclude>
-    <ClInclude Include="..\..\include\etl\wformat_spec.h">
-      <Filter>ETL\Utilities</Filter>
-    </ClInclude>
     <ClInclude Include="..\..\include\etl\multi_array.h">
       <Filter>ETL\Containers</Filter>
     </ClInclude>
@@ -774,6 +732,51 @@
     <ClInclude Include="..\..\include\etl\delegate_service.h">
       <Filter>ETL\Frameworks</Filter>
     </ClInclude>
+    <ClInclude Include="..\..\include\etl\cstring.h">
+      <Filter>ETL\Strings</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\include\etl\string_view.h">
+      <Filter>ETL\Strings</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\include\etl\u16string.h">
+      <Filter>ETL\Strings</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\include\etl\u32string.h">
+      <Filter>ETL\Strings</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\include\etl\wstring.h">
+      <Filter>ETL\Strings</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\include\etl\to_string.h">
+      <Filter>ETL\Strings</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\include\etl\to_u16string.h">
+      <Filter>ETL\Strings</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\include\etl\to_u32string.h">
+      <Filter>ETL\Strings</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\include\etl\to_wstring.h">
+      <Filter>ETL\Strings</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\include\etl\wformat_spec.h">
+      <Filter>ETL\Strings</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\include\etl\u32format_spec.h">
+      <Filter>ETL\Strings</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\include\etl\u16format_spec.h">
+      <Filter>ETL\Strings</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\include\etl\format_spec.h">
+      <Filter>ETL\Strings</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\include\etl\basic_format_spec.h">
+      <Filter>ETL\Strings</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\include\etl\basic_string.h">
+      <Filter>ETL\Strings</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="..\main.cpp">
@@ -1285,6 +1288,9 @@
     <Text Include="..\CMakeLists.txt">
       <Filter>Source Files</Filter>
     </Text>
+    <Text Include="..\..\todo.txt">
+      <Filter>Resource Files</Filter>
+    </Text>
   </ItemGroup>
   <ItemGroup>
     <Image Include="..\..\etl.ico">
diff --git a/todo.txt b/todo.txt
index 67db4df4..2fda3c72 100644
--- a/todo.txt
+++ b/todo.txt
@@ -1,4 +1,7 @@
 List of ideas for future development.
 
 delegate_timer (Variant of callback_timer)
+
 delegate_state_chart (Variant of state_chart)
+
+Finish secure containers