Within the ''action'' string of the DroppableWidget, the ''action'' string of the ButtonWidget and the ''action'' string of the LinkCatcherWidget, the <<.def modifier>> [[variable|Variables]] contains the modifier key(s) held during the drag-process.
The possible keys are ''meta'', ''ctrl'', ''shift'', ''alt'', ''meta'' and ''ctrl'', ''meta'' and ''shift'', ''meta'' and ''alt'', ''ctrl'' and ''shift'', ''alt'' and ''shift'', ''ctrl'' and ''alt'', ''ctrl'' and ''alt'' and ''shift'', ''meta'' and ''alt'' and ''shift'', ''meta'' and ''ctrl'' and ''shift'', ''meta'' and ''ctrl'' and ''alt'', ''meta'' and ''ctrl'' and ''alt'' and ''shift''