| Definition | Type | Referenced Entity | 
|---|
|  amount_of_substance_unit |  ENTITY |  named_unit | 
|  attribute_classification_item |  SELECT |  named_unit | 
|  classification_item |  SELECT |  named_unit | 
|  classification_item |  SELECT |  conversion_based_unit | 
|  conversion_based_unit |  ENTITY |  named_unit | 
|  convert_plane_angle_for_pair_from_radian |  FUNCTION |  conversion_based_unit | 
|  currency |  ENTITY |  named_unit | 
|  dependent_instantiable_named_unit |  RULE |  named_unit | 
|  derived_unit_element |  ENTITY |  named_unit | 
|  derive_dimensional_exponents |  FUNCTION |  named_unit | 
|  document_reference_item |  SELECT |  externally_defined_item | 
|  electric_current_unit |  ENTITY |  named_unit | 
|  externally_defined_dimension_definition |  ENTITY |  externally_defined_item | 
|  externally_defined_feature_definition |  ENTITY |  externally_defined_item | 
|  externally_defined_item_relationship |  ENTITY |  externally_defined_item | 
|  externally_defined_item_with_multiple_references |  ENTITY |  externally_defined_item | 
|  external_identification_item |  SELECT |  externally_defined_item | 
|  external_identification_item |  SELECT |  named_unit | 
|  external_identification_item |  SELECT |  externally_defined_conversion_based_unit | 
|  groupable_item |  SELECT |  named_unit | 
|  length_unit |  ENTITY |  named_unit | 
|  luminous_intensity_unit |  ENTITY |  named_unit | 
|  mass_unit |  ENTITY |  named_unit | 
|  named_unit |  ENTITY |  conversion_based_unit | 
|  organization_item |  SELECT |  externally_defined_item | 
|  plane_angle_for_pair_in_radian |  FUNCTION |  conversion_based_unit | 
|  plane_angle_unit |  ENTITY |  named_unit | 
|  ratio_unit |  ENTITY |  named_unit | 
|  same_as_item |  SELECT |  named_unit | 
|  si_unit |  ENTITY |  named_unit | 
|  solid_angle_unit |  ENTITY |  named_unit | 
|  subtype_exclusiveness_externally_defined_item |  RULE |  externally_defined_item | 
|  subtype_mandatory_externally_defined_item |  RULE |  externally_defined_item | 
|  thermodynamic_temperature_unit |  ENTITY |  named_unit | 
|  time_unit |  ENTITY |  named_unit | 
|  unit |  SELECT |  named_unit |