SDLR is a standard ERC-20 token. 1 SDLR = 1 gram of physical silver. Every SDLR has a corresponding ERC-3643 token locked in the vault behind it. The ERC-20 token cannot exist without it. When physical silver arrives in the vault, a corresponding ERC-3643 Allocated Token is minted on-chain and locked inside the Vault smart contract. Metal always enters the vault before tokens are minted, and a mint beyond registered collateral reverts on-contract. DOMA tokens exist only on Ethereum. Anyone can read total circulating supply in real time, directly from the chain, without asking DOMA for anything.