I recently came across a sytax restriction. Not sure if the TC have already discussed this. Consider the valid syntax: node_types <node_name>: derived from: <node_type_name> requirements: - <requirement_name> capability: <capability_type_name> relationship: type: <relationship_type_name> interfaces: <interface_name>: operations: <operation_name> inputs: <parameter_name> type: <datatype_name> value: ( get_property: [ SOURCE, .... ] } Now, note that the capability referenced by <capability_type_name> may have properties. However according to V2.0 draft Section 4.4.2 there does not seem to be a valid syntax to reference the capability property from within the get_property clause. There seems to be a need for a general purpose syntax to permit selection of a single parameter value from a valid TOSCA template of arbitrary depth and complexity; something like JSONPath or the less well supported YAMLPath. Regards Paul Jordan