This Handbook describes a set of principles and Standards-based approaches for specifying and achieving interoperable e health systems. It identifies - (a) guiding principles, goals, approaches and requirements for achieving e health interoperability;(b) a Standards-based framework and related concepts for specifying e health interoperability requirements;(c) recommended document components for specifying interoperable e health solutions and the role, content and uses for each of these components; and(d) guidelines for defining the capability of health care organizations to interoperate.