Most content within EATS is formed from AIR Documents, which are formatted as W3C XML content. Architected Messages, service requests and service responses, are encoded as AIR Documents. As are all element specifications in the database. Historical versions are also AIR Documents with their state defined in standardized, semantically "understood" properties. All AIR Documents share a common semantic base. All instance element specifications derive from that base.
Content, and messages, can be constructed, or deconstructed by means of a model specification for the element. Model specifications are provided in the form of meta data element specifications. Which are then used to encode and decode other elements.