Make an XP deprecation page for a VS error message target.

Author: Colin Robertson

docs/porting/TOC.md

@@ -15,6 +15,7 @@
 ### [Fix your dependencies on library internals](fix-your-dependencies-on-library-internals.md)
 ### [Floating-point migration issues](floating-point-migration-issues.md)
 ### [Use native multi-targeting in Visual Studio to build old projects](use-native-multi-targeting.md)
+### [Visual C++ features deprecated in Visual Studio 2019 preview](features-deprecated-in-visual-studio.md)
 ## [Introduction to Visual C++ for UNIX Users](introduction-to-visual-cpp-for-unix-users.md)
 ## [Porting from UNIX to Win32](porting-from-unix-to-win32.md)
 ## [Porting to the Universal Windows Platform (C++)](porting-to-the-universal-windows-platform-cpp.md)

docs/porting/features-deprecated-in-visual-studio.md

@@ -0,0 +1,17 @@
+---
+title: "Visual C++ features deprecated in Visual Studio 2019 preview"
+ms.custom: ""
+ms.date: "10/10/2018"
+ms.technology: ["cpp-language"]
+ms.topic: "conceptual"
+dev_langs: ["C++"]
+helpviewer_keywords: ["Features deprecated in Visual Studio 2019"]
+author: "corob-msft"
+ms.author: "corob"
+ms.workload: ["cplusplus"]
+---
+# Visual C++ features deprecated in Visual Studio 2019 preview
+
+## Support for Windows XP development
+
+The version of Visual C++ in Visual Studio 2019 preview 0 and later does not include support for creating code for Windows XP by using the v142 toolset. Support for Windows XP development by using the v141 toolset that shipped in Visual Studio 2017 is available as an optional component in the Visual Studio Installer. For information on how to install the v141 Windows XP platform toolset, see [Configuring programs for Windows XP](../build/configuring-programs-for-windows-xp.md).