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Common Alerting Protocol

This section contains information about the Common Alerting Protocol (CAP), an international standard that is used by IPAWS to send public alerts and warnings.

The CAP is a digital format for exchanging emergency alerts that allows a consistent alert message to be disseminated simultaneously over many different communications systems. FEMA worked with the Organization for the Advancement of Structured Information Standards (OASIS) to develop a standardized international technical data profile that defines a specific way of using the standard for the purposes of the Integrated Public Alert and Warning System (IPAWS).

Common Alerting Protocol (CAP) Implementation for IPAWS Fact Sheet

Benefits of CAP

As more systems are built or upgraded to CAP, a single alert can trigger a wide variety of public warning systems, increasing the likelihood that intended recipients receive the alert by one or more communication pathways. CAP provides the capability to include rich content, such as photographs, maps, video and more as well as the ability to geographically target alerts to a defined warning area, limited only by the capacity of the delivery system used. 

Because CAP provides the capability to incorporate both text and equivalent audio, CAP alerts can better serve the needs of hearing or visually impaired persons. Although IPAWS does not provide translation services, CAP does provide the capability to issue alerts in multiple languages.

Guidance and Technical Documents

Last Updated: 
07/16/2019 - 10:17