diff --git a/src/caosdb/common/models.py b/src/caosdb/common/models.py
index 5913ad72af20f3c040ab168082dc6b87e2769c1a..4894f9374eb75f121fee3058e2c031528c4a2f3b 100644
--- a/src/caosdb/common/models.py
+++ b/src/caosdb/common/models.py
@@ -5,9 +5,9 @@
 #
 # Copyright (C) 2018 Research Group Biomedical Physics,
 # Max-Planck-Institute for Dynamics and Self-Organization Göttingen
-# Copyright (C) 2020 Indiscale GmbH <info@indiscale.com>
+# Copyright (C) 2020-2022 Indiscale GmbH <info@indiscale.com>
 # Copyright (C) 2020 Florian Spreckelsen <f.spreckelsen@indiscale.com>
-# Copyright (C) 2020 Timm Fitschen <t.fitschen@indiscale.com>
+# Copyright (C) 2020-2022 Timm Fitschen <t.fitschen@indiscale.com>
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU Affero General Public License as
@@ -25,7 +25,14 @@
 # ** end header
 #
 
-"""missing docstring."""
+"""
+Collection of the central classes of the CaosDB client, namely the Entity class
+and all of its subclasses and the Container class which is used to carry out
+transactions.
+
+All additional classes are either important for the entities or the
+transactions.
+"""
 from __future__ import print_function, unicode_literals
 
 import re