There are two ways of getting event messages out of a sensor. The standard is SDEE, which is just XML that you can look inside to see the tags on each field. They like to call it "self documenting". The second (and more difficult because it requires you to tune each active signature) is syslog.
Here's an example of an SDEE message. I believe this is from a version 5.x sensor (it could be version 4, I don't see Risk Rating). Each time a new major version of software is release, new features are added and (if reportable) they show up as new fields in the SDEE messages.
Table of ContentsIntroductionVersion HistoryPossible Future
UpdatesDocuments PurposeNAT Operation in ASA 8.3+ SectionsRule Types
Network Object NATTwice NAT / Manual NATRule Types used per SectionNAT
Types used with Twice NAT / Manual NAT and Network Obje...
Table of Contents Introduction:This document describes details on how
NAT-T works. Background: ESP encrypts all critical information,
encapsulating the entire inner TCP/UDP datagram within an ESP header.
ESP is an IP protocol in the same sense that TCP an...