[EAS] Guidance for IPAWS CAP elements and sub-elements

[Sean Donelan]

This guidance attempts to follow the Common Alerting Protocol philosophy 
-- one CAP message is intended to be distributed by multiple alerting 
channels. The guidance is intended to improve the consistency of CAP 
messages across all IPAWS distribution channels. Some items improve 
interoperability with different implementations, such as specifying 
case-sensitive versus case-insensitive values. Other items would improve 
the public presentation of alerts, but don't affect the operation of the 
alert system.

Interoperability items are always the most difficult to reach agreement, 
because multiple choices are possible. Different choices may be correct 
but may not be interoperable. This guidance intentionally makes some 
choices which are different than individual alerting origination software, 
but I believe improve the overall alerting ecosystem across all 
stakeholders. That does not mean those vendors were incorrect. I hope 
those vendors and customers will consider making compatible changes.

Guidance for IPAWS Common Alerting Protocol (CAP) Elements and Sub-element 
Data (PDF) [33 pages]

https://www.donelan.com/eas