--- a/README	Thu Sep 07 17:40:49 2017 +0200
+++ b/README	Tue Sep 12 14:52:30 2017 +0200
@@ -6,6 +6,7 @@
 
 Use the Insert-Key to add a new task to track.
 (A *task* is called *project* within getan.)
+You will have to enter a project "key" and a project "description".
 
 Now select one of the projects with the arrow keys from your keyboard
 and press enter to start the clock. See ``INTRODUCTION`` for more keyboard
@@ -15,6 +16,22 @@
 by default getan will create ``~/.getan/time.db``.
 The ``scripts/`` will help to generate reports from them.
 
+Tree mode
+---------
+Getan supports a hierarchy of projects. A top level project key
+has only one character, once you starting using a second character
+as project key, it will be the next level down in the hierarchy.
+Example::
+
+    a    Top level project
+    aa   1st second level project
+    ab   2nd second level project
+    aba  Third level Project
+
+Use the switch_project_order key which is ``f2`` by default
+to cycle to the hierarchical view.
+
+
 Customization
 -------------