It's an old tradition in the cheesemaking biz to code long aged cheeses on the surface. That way you always know what you are looking at in the curing rooms. "G" for Gore-Dawn-Zola is made in the 3rd month of the year on the 5th week on a wednesday (we only make cheese one day a week, if we can help it).
When you remove the food-grade letters/numbers there is an impression in the fresh cheese.
Once these have aged, the impression should be even more pronounced. I am working on a logo to add, as other Vermont cheesemakers do, but since "moo cows" have been taken, it needs a bit of a think before doing. Maybe a tractor? Corn stalk? Mountain range? The logo lady?