diff --git a/src/CalcViewModel/Common/Utils.cpp b/src/CalcViewModel/Common/Utils.cpp
index 1bc3307c..b628da58 100644
--- a/src/CalcViewModel/Common/Utils.cpp
+++ b/src/CalcViewModel/Common/Utils.cpp
@@ -81,7 +81,7 @@ void Utils::RunOnUIThreadNonblocking(std::function<void()>&& function, _In_ Core
 }
 
 // returns if the last character of a wstring is the target wchar_t
-bool Utils::IsLastCharacterTarget(_In_ wstring const &input, _In_ wchar_t target)
+bool Utils::IsLastCharacterTarget(_In_ wstring const &input, wchar_t target)
 {
     return !input.empty() && input.back() == target;
 }
diff --git a/src/Calculator/Common/TitleBarHelper.cpp b/src/Calculator/Common/TitleBarHelper.cpp
index 18e8be94..53ad27fb 100644
--- a/src/Calculator/Common/TitleBarHelper.cpp
+++ b/src/Calculator/Common/TitleBarHelper.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) Microsoft Corporation. All rights reserved.
+// Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
 #include "pch.h"
@@ -14,7 +14,7 @@ using namespace Windows::ApplicationModel::Core;
 using namespace Windows::Foundation;
 using namespace Windows::UI::Xaml;
 
-unique_ptr<TitleBarHelper> TitleBarHelper::CreateTitleBarHelperIfNotDocked(FrameworkElement^ customTitleBar)
+unique_ptr<TitleBarHelper> TitleBarHelper::CreateTitleBarHelperIfNotDocked(_In_ FrameworkElement^ customTitleBar)
 {
     return (App::GetAppViewState() == ViewState::DockedView)
         ? nullptr
diff --git a/src/Calculator/Views/Calculator.xaml.h b/src/Calculator/Views/Calculator.xaml.h
index 3ec3feac..4af6a7e9 100644
--- a/src/Calculator/Views/Calculator.xaml.h
+++ b/src/Calculator/Views/Calculator.xaml.h
@@ -1,4 +1,4 @@
-// Copyright (c) Microsoft Corporation. All rights reserved.
+// Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
 #pragma once
@@ -68,7 +68,7 @@ namespace CalculatorApp
         void SetDefaultFocus();
 
     private:
-        void OnLoaded(Platform::Object^ sender, Windows::UI::Xaml::RoutedEventArgs^ e);
+        void OnLoaded(_In_ Platform::Object^ sender, _In_ Windows::UI::Xaml::RoutedEventArgs^ e);
 
         void LoadResourceStrings();
 
diff --git a/src/Calculator/Views/MainPage.xaml.cpp b/src/Calculator/Views/MainPage.xaml.cpp
index 1b7541ce..6fd049f2 100644
--- a/src/Calculator/Views/MainPage.xaml.cpp
+++ b/src/Calculator/Views/MainPage.xaml.cpp
@@ -86,7 +86,7 @@ MainPage::MainPage() :
     }    
 }
 
-void MainPage::OnNavigatedTo(NavigationEventArgs^ e)
+void MainPage::OnNavigatedTo(_In_ NavigationEventArgs^ e)
 {
     if (m_model->CalculatorViewModel)
     {
@@ -409,7 +409,7 @@ void MainPage::OnNavPaneClosed(_In_ MUXC::NavigationView^ sender, _In_ Object^ a
     this->SetDefaultFocus();
 }
 
-void MainPage::OnAboutButtonClick(Object^ sender, ItemClickEventArgs^ e)
+void MainPage::OnAboutButtonClick(_In_ Object^ sender, _In_ ItemClickEventArgs^ e)
 {
     ShowAboutPage();
 }
diff --git a/src/Calculator/Views/TitleBar.xaml.h b/src/Calculator/Views/TitleBar.xaml.h
index 85a360b7..d0dc345f 100644
--- a/src/Calculator/Views/TitleBar.xaml.h
+++ b/src/Calculator/Views/TitleBar.xaml.h
@@ -1,4 +1,4 @@
-// Copyright (c) Microsoft Corporation. All rights reserved.
+// Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
 #pragma once
@@ -14,8 +14,8 @@ namespace CalculatorApp
 
         void SetTitleBar();
     private:
-        void OnLoaded(_In_ Object^ sender, Windows::UI::Xaml::RoutedEventArgs^ e);
-        void OnUnloaded(_In_ Object^ sender, Windows::UI::Xaml::RoutedEventArgs^ e);
+        void OnLoaded(_In_ Object^ sender, _In_ Windows::UI::Xaml::RoutedEventArgs^ e);
+        void OnUnloaded(_In_ Object^ sender, _In_ Windows::UI::Xaml::RoutedEventArgs^ e);
 
         void Initialize();
         void RegisterForLayoutChanged();