Wherever possible try to describe the position of the stone relative to the hallmark. In order for the position of the stone to be accurately described it is essential that all parties hold the ring the same way up. Firstly you will need an eye glass so that you can read the hallmark on the ring. Look at the hallmark through an eyeglass and hold the ring in front of you so that hallmark is the right way up with the head of the ring on top and facing towards you.
A sketch of the ring would be another option to indicate the location missing stone.
Maker-Mends will take a digital image of all proceeded work and this is kept on file.
NB. It is always a good idea whilst looking for the hallmark to examine the general condition of the settings and point out any observations to the customer that may have lead to the stone falling out such as missing or worn claw. Record the details on the repair slip.