docs: function parse_RgceArea(blob, length, opts) {
  	var w = 2;
  	if(opts) {
  		if(opts.biff >= 2 && opts.biff <= 5) return parse_RgceArea_BIFF2(blob, length, opts);
  		else if(opts.biff == 12) w = 4;
  	}
  	var r=blob.read_shift(w), R=blob.read_shift(w);
  	var c=parse_ColRelU(blob, 2);
  	var C=parse_ColRelU(blob, 2);
  	return { s:{r:r, c:c[0], cRel:c[1], rRel:c[2]}, e:{r:R, c:C[0], cRel:C[1], rRel:C[2]} };
  }