Complicated
Ryu had never formally learned any Blacksmithing, obviously. So, the Smithing Runes he understood were exactly zero. However, he didn't even consider this to be a problem at this moment. In fact, he felt that his own style of refinement couldn't rely on the methods of others. If he wanted this to work properly, he would have to formulate his own system.
To anyone else, this might have felt like a daunting task. But, to Ryu, it filled him with excitement he had never felt before. And, he knew exactly where he should start.
The Fundamental Runes of the world were the foundation that formulated the world. All that was, all that would be, and all that had been was structured beneath the laws of these Runes.