Copy and Paste actions can be performed with more than one category with the help of categories tool-bar or context menu.
First you have to copy selected categores and go to the category you
need (highlight) to paste. You'll see Copy category parameters, select
data you wish to copy to clipboard.
When you're pasting category (ies), you're creating new ones with new
IDs. When you press Paste button the following form appears:
You have to choose whether to paste categories to the selected
category (make sure you highlight it) or to paste categories to the root