Abstract: This document describes the OASIS Common Alerting Protocol (CAP) standard, review its history and current status, and propose some directions for its future application and development. This XML content standard specifies a canonical data model for alerting, warning and notification messages. By abstracting the essential elements of effective warning messages from the underlying delivery technologies, CAP simplifies the integration of diverse warning delivery systems and provides a simple template for the creation of alerts and warnings. CAP is being used in a variety of warning systems and applications, but its full potential has yet to be exploited.