Domain represents a logical set of instantiated Elements found within object model. You can not reference an Element not instantiated within model's Elements collection. Domains may form hierarchical structures (binary trees), each of them referencing 0..n existing Elements. Each domain may also reference it's parent domain, thus promoting it to a superset of referenced elements via inheritance.

Logical sets of elements may get utilized by application for various purposes, i.e. to form specific topologies, denote hierarchy of referenced elements, etc.

[SerializableAttribute]
public class Domain : Feature

<SerializableAttribute>
Public Class Domain
	Inherits Feature

[SerializableAttribute]
public ref class Domain : public Feature

[<SerializableAttribute>]
type Domain =  
    class
        inherit Feature
    end