diff --git a/mercurial/configitems.py b/mercurial/configitems.py
new file mode 100644
--- /dev/null
+++ b/mercurial/configitems.py
@@ -0,0 +1,21 @@
+# configitems.py - centralized declaration of configuration option
+#
+#  Copyright 2017 Pierre-Yves David <pierre-yves.david@octobus.net>
+#
+# This software may be used and distributed according to the terms of the
+# GNU General Public License version 2 or any later version.
+
+from __future__ import absolute_import
+
+class configitem(object):
+    """represent a known config item
+
+    :section: the official config section where to find this item,
+       :name: the official name within the section,
+    :default: default value for this item,
+    """
+
+    def __init__(self, section, name, default=None):
+        self.section = section
+        self.name = name
+        self.default = default