What shortcut key is used to switch from Normal Select Mode to Add/Remove Mode?

The Spacebar is the correct shortcut key used to switch from Normal Select Mode to Add/Remove Mode. In Solid Edge, this functionality enhances the user's ability to select multiple elements efficiently. When you're in Normal Select Mode, clicking on entities selects them individually. However, when you press the Spacebar, it toggles to the Add/Remove Mode, allowing you to quickly add to your current selection by clicking on additional entities or remove them by clicking on already selected entities. This feature is particularly useful in complex assemblies where managing selections can be cumbersome, as it streamlines the user interaction with the software, making it more intuitive to modify selections without having to navigate through menus.