--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/doc/book/devrepo/datamodel/baseschema.rst	Thu Jan 08 22:11:06 2015 +0100
@@ -0,0 +1,42 @@
+.. _pre_defined_entity_types:
+
+Pre-defined entities in the library
+-----------------------------------
+
+The library defines a set of entity schemas that are required by the system
+or commonly used in *CubicWeb* instances.
+
+
+Entity types used to store the schema
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+* _`CWEType`, entity type
+* _`CWRType`, relation type
+* _`CWRelation`, relation definition
+* _`CWAttribute`, attribute relation definition
+* _`CWConstraint`,  `CWConstraintType`, `RQLExpression`
+
+Entity types used to manage users and permissions
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+* _`CWUser`, system users
+* _`CWGroup`, users groups
+
+Entity types used to manage workflows
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+* :ref:`Workflow <Workflow>`, workflow entity, linked to some entity types which may use this workflow
+* _`State`, workflow state
+* _`Transition`, workflow transition
+* _`TrInfo`, record of a transition trafic for an entity
+
+Other entity types
+~~~~~~~~~~~~~~~~~~
+* _`CWCache`, cache entities used to improve performances
+* _`CWProperty`, used to configure the instance
+
+* _`EmailAddress`, email address, used by the system to send notifications
+  to the users and also used by others optionnals schemas
+
+* _`Bookmark`, an entity type used to allow a user to customize his links within
+  the instance
+
+* _`ExternalUri`, used for semantic web site to indicate that an entity is the
+  same as another from an external site