The StartFolded property of the GroupAttribute class determines whether the group should initially appear in a collapsed state. When set to true, the group will start closed, hiding its contents until expanded by the user. This can be useful for organizing and managing large sets of properties or settings in a user interface, allowing for a cleaner and more manageable display.

To use the StartFolded property, apply the GroupAttribute to a class or member and set the StartFolded property to true or false depending on whether you want the group to start in a folded state.