--- a/doc/book/en/admin/instance-config.rst	Mon Jan 31 17:48:57 2011 +0100
+++ b/doc/book/en/admin/instance-config.rst	Tue Feb 01 10:29:56 2011 +0100
@@ -4,6 +4,11 @@
 Configure an instance
 =====================
 
+On a Unix system, the instances are usually stored in the directory
+:file:`/etc/cubicweb.d/`. During development, the
+:file:`~/etc/cubicweb.d/` directory is looked up, as well as the paths
+in :envvar:`CW_INSTANCES_DIR` environment variable.
+
 While creating an instance, a configuration file is generated in::
 
     $ (CW_INSTANCES_DIR) / <instance> / <configuration name>.conf