- bom:
	+ xy-unit
	+ xy-in-mm

- gcode:
	+ dpi, Resolution of intermediate image (pixels/inch),
	+ mill-depth, Milling depth
	+ safe-Z, Safe Z for traverse move
	+ tool-radius, Milling tool radius compensation
	+ drill-depth, Drilling depth
	+ measurement-unit, Measurement unit

- gerber:
	+all-layers, Output all layers, even empty ones,
	+copy-outline, Copy outline onto other layers,

- nelma:
	+ dpi, Horizontal scale factor (grid points/inch),
	+ copper-height, Copper layer height (um),
	+ substrate-height, Substrate layer height (um),
	+ substrate-epsilon, Substrate relative epsilon,

- png:
	(Please test with png file format)
	+ dpi, Scale factor (pixels/inch). 0 to scale to specified size,
	+ as-shown, Export layers as shown on screen,
	+ {monochrome, Convert to monochrome,
	+ only-visible, Limit the bounds of the PNG image to the visible items,
		(turn off some layers!)
	+ use-alpha, Make the background and any holes transparent,
	+ png-bloat, Amount (in/mm/mil/pix) to add to trace/pad/pin edges (1 = 1/100 mil),
	+ photo-mode, Photo-realistic export mode,
	+ photo-flip-x, Show reverse side of the board, left-right flip,
	+ photo-flip-y, Show reverse side of the board, up-down flip,

- eps:
	+ eps-scale, EPS scale,
	+ as-shown, Export layers as shown on screen,
	+ monochrome, Convert to monochrome,
	+ only-visible, Limit the bounds of the EPS file to the visible items,

- ps:
	+ drill-helper, Print a centering target in large drill holes,
	+ align-marks, Print alignment marks on each sheet,
	+ outline, Print outline on each sheet,
	+ mirror, Print mirror image of every page,
	+ fill-page, Scale board to fill page,
	+ auto-mirror, Print mirror image of appropriate layers,
	+ ps-color, Prints in color,
	+ ps-bloat, Amount to add to trace/pad/pin edges,
	+ ps-invert, Draw objects as white-on-black,
	+ scale, Scale value to compensate for printer sizing errors (1.0 = full scale),