diff --git a/openerp/tests/__init__.py b/openerp/tests/__init__.py
index 6d29053b93c..dbdd2ccd024 100644
--- a/openerp/tests/__init__.py
+++ b/openerp/tests/__init__.py
@@ -1,14 +1,32 @@
 # -*- coding: utf-8 -*-
-import unittest2
+"""
+Tests for the OpenERP library.
+
+This module groups a few sub-modules containing unittest2 test cases.
+
+Some of those test sub-modules are explicitely listed in the `fast_suite`
+variable.  Most of the tests should be considered fast enough to be included in
+that `fast_suite` list and only tests that take a long time to run (e.g. more
+than a minute) should not be listed.
+
+Some other test sub-modules are sanity checks explicitely listed in the
+`checks` variable. These test sub-modules are invariants that must be
+full-filled at any time. They are expected to always pass: obviously they must
+pass right after the module is installed, but they must also pass after any
+other module is installed, after a migration, or even after the database was
+put in production for a few months.
+"""
 
 import test_orm
 import test_ir_sequence
 import test_xmlrpc
 
-# Explicit declaration list of test sub-modules.
-suite = [
+fast_suite = [
     test_xmlrpc, # Creates a database
     test_ir_sequence, # Assume an existing database
+    ]
+
+checks = [
     test_orm, # Assume an existing database
     ]
 
diff --git a/openerp/tests/test_xmlrpc.py b/openerp/tests/test_xmlrpc.py
index c24d6ba706e..dfed851dbe3 100644
--- a/openerp/tests/test_xmlrpc.py
+++ b/openerp/tests/test_xmlrpc.py
@@ -12,7 +12,6 @@ import xmlrpclib
 
 import openerp
 import common
-import core
 
 DB = common.DB
 ADMIN_USER = common.ADMIN_USER
@@ -23,7 +22,7 @@ setUpModule = common.start_openerp
 
 tearDownModule = common.stop_openerp
 
-class test_xmlrpc(core.RpcCase):
+class test_xmlrpc(common.RpcCase):
 
     def test_00_xmlrpc_create_database_polling(self):
         """