Prototype controls: Ctrl+N/O/S = new/open/save · drawings recover automatically after refresh · select an object, then click a white grip to edit it · L = line · PL = polyline · REC = rectangle · C = circle; choose 2P/3P before the first point or D after the center · A = three-point arc · M = move · CO = copy · RO = rotate · SC = uniform scale · MI = mirror · type R after the RO/SC base point for reference mode · O = offset · F = fillet · CHA = chamfer · TR = trim · EX = extend · J = join lines and open polylines end to end · X = explode a polyline or rectangle into lines · ST = stretch the vertices inside a crossing window · E = erase · use the Layers panel to create, rename, color, hide, lock, assign, and safely delete layers · Enter or Space finishes; Esc cancels and discards · Enter/Space/right-click at an empty prompt repeats the last command · type C to close or U to step back during a line or polyline · DLI = linear dimension · DAL = aligned dimension · DRA = radius dimension · DDI = diameter dimension · DST = dimension style · T = text · DI = distance · AA = area (type O for a single object) · ID = point · LI = list selected · UN opens Drawing Units; distances accept 5'6-1/2", 3-1/2, and 150mm · F8 = ortho · F10 = polar tracking, with the increment beside the button · SNAP toggles object snapping and the readout beside it chooses which snaps are active · Ctrl+Z/Y cancels an active command first, then undoes/redoes