Some of Whorld's dialogs allow multiple items to be selected at once. The interface is common to all Windows applications, but it's described here anyway.
|Single item||Left-click it.|
|Contiguous group||Left-click the first item, and then Shift+left-click the last item. Shift+left-click can also expand or trim an existing selection.|
|Non-contiguous group||Ctrl+left-click each item. To remove a item from the selection, Ctrl+left-click it again.|
|All items||Left-click any item, and press Ctrl+A.|