The user clicks twice or drags in a drawing window, to define a rectangle. The rectangle is automatically stored in register 0, of the eight rectangle registers that are available in pop-ups that use rectangle entry. Thus, pop-ups such as the Format Conversion panel, can load this rectangle by pressing the R button to the left of the window entry area, and selecting Reg 0.
After the rectangle is defined, the Export Control pop-up appears, preconfigured with the rectangle, and set for flattening, windowing, and clipping. The user may choose an output format and make any other desired changes, then press Write File. This will cause prompting for the name of the output file, which will be created if the user provides a valid name and no errors occur.