Within the scope of the instantiating Namespace, InstanceID opaquely and uniquely identifies an instance of this class. In ...

Within the scope of the instantiating Namespace, InstanceID opaquely and uniquely identifies an instance of this class. In order to ensure uniqueness within the NameSpace, the value of InstanceID SHOULD be constructed using the following 'preferred' algorithm:  :  Where  and  are separated by a colon ':', and where  MUST include a copyrighted, trademarked or otherwise unique name that is owned by the business entity creating/defining the InstanceID, or is a registered ID that is assigned to the business entity by a recognized global authority. (This is similar to the _ structure of Schema class names.) In addition, to ensure uniqueness  MUST NOT contain a colon (':'). When using this algorithm, the first colon to appear in InstanceID MUST appear between  and .    is chosen by the business entity and SHOULD not be re-used to identify different underlying (real-world) elements. If the above 'preferred' algorithm is not used, the defining entity MUST assure that the resultant InstanceID is not re-used across any InstanceIDs produced by this or other providers for this instance's NameSpace.