I am now placing a proof mark on the blades on the side where I place the steel type designation (pictures 1,2 and 3).
I have been proof testing my blades and fittings for twenty years now (pictures 8 and 9)
The idea comes from the old British officer's sabres, which were proof marked inside a six point star (pictures 4, 5 and 6). The triangle pointing downwards is the female (or water)  and the triangle pointing upwards is the male (or fire) in alchemaic practice. Now of course the proof mark is available to everyone, not just officers.
I simplified the six point star into six dots around the outside connected by a circle. They mean moving in a clockwise direction: Life, Loyalty, Knowledge, Wisdom, Understanding and Love (picture 7)
A lot of these words are missing from today's knife making community. I hope that this small detail will have effect on my clients and the knowledge that the blade they order from me has had the very best quality control.