The historical picture of the Department of Veteran’s Affairs VISTA EHR information architecture, given in the page on Developmental Models depicts the state of this Website,  has advanced further even though it  still remains the prime example of an integrated EHR enterprise information architecture in the nation. Since it was also the model for the Department of Defense CHCS architecture, it is not surprising that these two federal healthcare agencies have now developed a communication architecture (see the FHIE Segment under this Federal Healthcare Agency Implementation branch). This example of the interoperability of quite different organizations, is critical in showing how the various common conventions documented in the standards can be assembled to yield transparently interoperating global healthcare information architectures. For that to happen, the conceptual content must utilize the same conventions. The practical example is that a military service member, or a veteran, can enter any of the healthcare facilities of those departments and have his or her current record accessed within minutes. Such a capability allows the DVA facilities to be used as contingency backups in national emergencies. It also allows the DVA to access the historic patient record of veterans who served some time in the past in order to ascertain the history of a health condition which may have arisen during military service. This becomes a tangible example of what has been called “the Longitudinal Healthcare Record”.