This field set is meant to facilitate pivoting around a piece of data.
Some pieces of information can be seen in many places in an ECS event. To facilitate searching for them, store an array of all seen values to their corresponding field in
A concrete example is IP addresses, which can be under host, observer, source, destination, client, server, and network.forwarded_ip. If you append all IPs to
related.ip, you can then search for a given IP trivially, no matter where it appeared, by querying
All of the IPs seen on your event.