When the EnableFilterModeSelection property is set to true, the ShoppingCartQuickEntryControl control will present the shopper with a Filter Mode Selector interface that allows them to switch between an "Exact" and "Search" mode.
By default, the property value is false, which hides the Filter Mode Selector completely from view.
When the shopper first visits a page with the ShoppingCartQuickEntryControl is present, and the property value is true, the initial mode selection will be set the value of the StockCodeFilterMode, and if the value is set to "Exact" the search option will only be available as a "Contains" search.