This example demonstrates a drag-and-drop interface for organizing items into hierarchical collections, built with custom HTML elements and the HTML5 Drag and Drop API. Users can drag individual items or multiple selected items between containers, with items either moving or cloning depending on the source container. The interface includes collapsible collection groups, delete buttons, and buttons to save and restore connection states. Code uses custom elements (`vc-dragitem`, `vc-dragcontainer`, `vc-dragclosebutton`, `vc-dragdeletebutton`) and embedded SVG graphics inside draggable items.