The drawing window has three operating modes:
You switch mode with the Mode command button. It brings up the mode switch dialog. The three round buttons denote the operating mode. With the two option list you select the point type or the line type. When you select a point type, the dialog switches automatically to Point insert mode. Similarly, if you select a line type it switches to Line insert mode. With the orientation dial you choose the orienttation of orientable points (entrance, air-draught, and water-flow).