[Dan_San_Abbott]

BarkhornXX:
On 17 March 1918, the Flugzeugmeisterei of Idflieg issued a directive to change the cross style from the Iron Cross form to the balken cross, (balken = beam). An undimensioned illustration accompanied the directive. This caused confusion with the manufacturers and they requested more information. The Field units went ahead and started changing the crosses on the airplanes. This resulted in a wide variety of cross forms and styles as each unit painter interpreted the directive.
On 24 March 1918, Idflieg was a lttle more specific and stated the cross form should be a ratio of 4:1 length to width and the white border would be 150 mm wide.
On 10 April 1918, Idflieg issued a third order that specified the cross sizes to be used for the rudder, fuselage and wings. The size for the rudder 400 mm, for the fuselage, 600 and the wings 1000mm. The white border was 150mm wide. All these changes created havoc in the field, which resulted in a wide variety of balken crosses.
To complete the cross story, on 4 June 1918 the hrizontal arm the the vertical latin cross with an a ratio of 4:5 was introduced. The vertical arm was to be full chord of the wing and full depth of the side of the fuselage.
The arm width was a ratio 8:1 of the vertical. The white border width was reduced to a ratio of 4:1 the width of the arm. The horizontal arm was to be the same wide as the vertical arm. The wing crosses are to be placed at the wing tips. On the Fok.D.VII, OAW did this, but, Fokker and Albatros did not.
Finally on 25 June 1918 the final form of the Latin cross was specified, the horizontal arm was to be that 1:1 ( both the same.) of the vertical arm. The width of the arm was to be a ratio of 8:1 of the vertical/ horizontal arms. The white border width to be a ratio of 4:1 of the vertical/horizontal arms. The cross was to be full chord of the wing and side of the fuselage.
This gives you the whole story in a nutshell.
Blue skies,
Dan-San