Meta-data--What do you use it for? Examples?

I’m fairly new to Scrivener, currently writing a short story. I see this large space in the lower right of my screen labelled “Custom Meta-Data”. I’m sure it must be a useful feature, but I’d like to have other writers show me how they use it.

Thanks.

Date, location, POV, Sub-plot/Main Plot. Anything you want an additional column for in the Outliner, really. I feel like that’s the biggest advantage, really, since you get only one column for Label and Status, but you can have an additional column for every Custom MetaData you create.