Standardized coding. The first challenge is standardizing the coding and formats for clinical information. Information systems must recognize and translate different coding schemes for clinical encounters, using a medical logic engine that recognizes different clinical terminology for the same problem. Because new terminology and knowledge are being constantly created, the medical knowledge architecture must be flexible enough to permit continual updating with professional consensus. However, getting dozens of clinical disciplines and technology vendors to agree on needed standardization of clinical coding as well as on standardization of the technical specifications of information systems, so that systems from different vendors can "inter-operate," is akin in complexity and politics to negotiating an international trade agreement.