Where it sits in that target's log.
The channel or nick it belongs to, as the server spells it.
The channel.
The channel.
The channel.
The channel.
What they were called.
What they are called now.
The channel.
The channel or person.
The message reacted to.
Where the message is.
The message deleted.
Where the message was.
The key that changed.
Whose metadata changed.
Who it describes.
What it was called.
What it is called now.
What changed, for a host that wants to react without diffing the whole model.