Quicktime embedded keykode metadata

In Resolve 15, in the metadata window for a Quicktime file, there's a field for keykode. I haven't yet seen a Quicktime file that has this metadata though. Does anyone know what the field inside the quicktime file is called, and would you happen to have a sample quicktime file with keykode embedded?

We're looking for a solution with our scanner to try to get keykode metadata embedded in Quicktime files. Right now, it only works for DPX, but would greatly ease conforming when working with film-originated material that has keykode.

Thanks!

-perry

[DavidS]

I don't see anything in the apple quicktime documentation covering this, but of course anyone could have added new fields themselves. However unless someone standardises that's not helpful.