XF 1.5 ACP Preferences - Style not the one I picked?

OK, ready for a dumb question?

When I look at individual users settings in the ACP, under the tab "Preferences" I see in the Style field: (Use default style).


Does that mean they are using the style called Default Style, or that they are using the default style I selected in Appearance/Styles, in this case Core Child?

I almost didn't ask, but I want to make totally sure...


Name withheld to protect the reputation of the innocent