Unit
Note: There is a newer version of this specification see VEC 2.1.0
A precisely specified quantity in terms of which the magnitudes of other quantities of the same kind can be stated. The different systems to define units are represented by the subclasses of this class (e.g. SIUnit, ImperialUnit).
General Information
Attribute  Value 

Owner  physical_information 
Applied Stereotype  constant 
Base Classifier  
Is Abstract  true 
Derived Classifiers  CompositeUnit, CustomUnit, IECUnit, ImperialUnit, OtherUnit, SIUnit, USUnit 
Attributes
Name  Type  Mult.  Description  Owning Classifier 

exponent  Integer  0..1  Defines the exponent with which this unit instance should be used. In order to define square meters for example, the SIUnit "metre" with an exponent of 2 will be used. If no exponent is defined it is equivalent to the value 1. 
Unit 
Incoming Relations
Type  Mult.  Role  Mult.  Description 

BuildingBlockSpecification2D  0..*  baseUnit  1  
BuildingBlockSpecification3D  0..*  baseUnit  1  
LocalGeometrySpecification  baseUnit  1  The Unit in which all coordinates (e.g. cartesian points) are defined. Shall be a unit of length (e.g. millimetre). 

CompositeUnit  factors  1..*  References the Units that are used as factors to create the CompositeUnit. 

VecContent  1  unit  0..*  Specifies the Units used in the VECfile. 
ValueWithUnit  0..*  unitComponent  1  References the unit of the value. 
Dimension  0..*  unitComponent  1 