Index: trunk/doc/user/06_feature/ddraft/index.html
===================================================================
--- trunk/doc/user/06_feature/ddraft/index.html	(revision 18831)
+++ trunk/doc/user/06_feature/ddraft/index.html	(revision 18832)
@@ -11,6 +11,12 @@
 The purpose of ddraft is to provide actions and GUI tools to help users
 drawing precise 2d drafts. Many of the features in ddraft are very similar
 to those found in standard 2d CAD packages.
+<p>
+Ddraft uses the following coordinate system (when looked from the top
+of the board):
+<p>
+<img src="coord_sys.png" alt="ddraft coordinate system: upper left corner is 0;0, x+ is tot he right, y+ is down, 0 deg is at 3 o'clock and increases clockwise">
+<p>
 
 
 </body>