A string that forms one third of the unique key for the entity being represented. Being the 'id' part of the globally unique key 'type/source/id', this value should identify a specific entity of the given 'type' from the given 'source'.

public abstract string Id { get; }

Public MustOverride ReadOnly Property Id As String
	Get

public:
virtual property String^ Id {
	String^ get () abstract;
}