Copying index cards

I have two outlines in the same project, and, with the editing screen split and in corkboard mode, want to copy index cards from one panel/outline to the other. I can move cards (using drag and drop) and had hoped that pressing the command or option key would turn a move into a copy, but that doesn’t appear to happen. Any suggestions?

Hit cmd-D to duplicate the card and then drag the duplicate to the other editor.

Hope that helps.

All the best,
Keith

That helps a lot. Thanks.