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+## TOSCA Interface Definition
+
+This directory implements a TOSCA interface for XOS,
+which can be extended to include specifications for
+service models added to XOS. The directory is organized
+as follows:
+
+ * custom_types -- Defines schema for XOS-specific models.
+   * `.m4` files are source.
+   * `.yaml` files are generated.
+ * definitions -- Defines schema for TOSCA's base models.
+ * resources -- Translates TOSCA specification to Django API.
+ * sample -- Example TOSCA models.