ник: osmor
По русски это называется "несвязанное выделение" :-) и может принимать значения:
The MultiSelect property uses the following settings.
Setting Visual Basic Description
None 0 (Default) Multiple selection isnt allowed.
Simple 1 Multiple items are selected or deselected by clicking them with the mouse or pressing the SPACEBAR.
Extended 2 Multiple items are selected by holding down SHIFT and clicking them with the mouse or by holding down SHIFT and pressing an arrow key to extend the selection from the previously selected item to the current item. You can also select items by dragging with the mouse. Holding down CTRL and clicking an item selects or deselects that item.