Thanks for the help with the documents Talonite.
I ran some tests, however, and the aiming guides don't seem to work as advertised
Dropping from 50 meters using the second indicator from the top works almost perfectly.
However, dropping from 100 meters, I had to use an area between the 3rd and 4th indicators.
From 100 meters, using the 3rd indicator led to the bombs falling short. The same occured at 200 using the 4th indicator.
All drops were done at almost exactly 300 kph, straight and level.
I don't know what the reason for the differences could be, but for now, I think I'll stick to dropping from 50-100 meters.