+## Target reader of this document
+
+This document is intended for developers and system integrators who
+need to know, how Window manager works and how it is to be used.
+
+### Scope of this Document
+
+This document covers Window manager that was implemented for TMC and
+delivered to the Automotive Grade Linux (AGL) project. It includes its
+implementation details, concepts of operation, configuration and usage.
+
+It does not include
+
+- document of the underlying architecture, see
+ [HMI-Framework](https://wiki.automotivelinux.org/hmiframework).
+
+- document of the AGL application framework and its technologies,
+ see [AGL Application
+ Framework](https://wiki.automotivelinux.org/agl-distro/app-framework).
+
+- document of HomeScreen, see
+ [HomeScreen](./3_1-HomeScreen-Guide.html).
+
+It is highly recommended to have a good understanding of these documents
+and projects before using Window manager.