A Viewpoint is a specification of the conventions and rules for constructing and using a view for the purpose of addressing a set of stakeholder concerns. The languages and methods for specifying a View can reference methods and languages in another Viewpoint. They specify the elements expected to be represented in the view that may be formally or informally defined.
A Viewpoint has a Method property which describes the expectation of what stakeholder(s) wish to see exposed from the model, how the stakeholder wishes the information to be structured and presented, and in what kind of artifact the stakeholder wants to consume the information. It is the set of rules that describe how the view should express the information from the model to address the stakeholder concerns. The methods are used to construct the Views for the Viewpoint.