Recommended Reading:
cap:addresses
cap:alert
cap:altitude
cap:area
cap:areaDesc
cap:audience
cap:category
cap:ceiling
cap:certainty
cap:circle
cap:code
cap:contact
cap:derefUri
cap:description
cap:digest
cap:effective
cap:event
cap:eventCode
cap:expires
cap:geocode
cap:headline
cap:identifier
cap:incidents
cap:info
cap:instruction
cap:language
cap:mimeType
cap:msgType
cap:note
cap:onset
cap:parameter
cap:polygon
cap:references
cap:resource
cap:resourceDesc
cap:responseType
cap:restriction
cap:scope
cap:sender
cap:senderName
cap:sent
cap:severity
cap:size
cap:source
cap:status
cap:urgency
cap:uri
cap:value
cap:valueName
cap:web