Embed owners name in Raw file

[eavesphoto]

I'm working with a photographer for this week with an IQ 280 and capture 8.1.1
We're working on a campaign, and the client has requested that we give them the raw files.
Is there a way that the owners name or copyright year be embedded in the raw files?

I'm not sure if this client knows how to deal with XMP files, it just seems strange that you can embed GPS info in the IQ but you can't embed the owners name.
Capture one is not in the clients workflow, they're probably using Adobe camera raw.
The photographer wants to do this, just like you can do it with his Canon 5D Mark III.