This part will give data on the subjects handled by this website.
Ordnance codes
Be aware that there are over 8.000 codes, so we can not list them all. We have the book, so you can mail your questions.
Optical markings
Here we present some markings found on optical equipment.
Rangefinding procedure
A brief explanation how the simple range finding procedure works.
Fairy tales
Some notes on common misunderstandings, mostly presented to try to raise the value of optical devices on online auctions.