You're on the right track.
The old bakers used the word Arkady in reference to the mineral yeast food that they commonly added to their doughs. Mineral yeast food (MYF) is a mixture of calcium salts, ammonium salts, and back then potassium bromate. It was typically added at a level of 0.25 to 0.5% of the total flour weight. Today, most bakers don't use MYF, instead, they use calcium sulfate instead.
Tom Lehmann/The Dough Doctor