n) {
        case "show": {
          hidePanel(panel);
          /** @type {HTMLElement} */
          const dfn = target.closest("dfn, .index-term");
          panel = document.getElementById(`dfn-panel-for-${dfn.id}`);
          const coords = deriveCoordinates(event);
          displayPanel(dfn, panel, coords);
          break;
        }
        case "dock": {
          panel.style.left = null;
          panel.style.top = null;
          panel.classList.add("docked");
          break;
        }
        c