| Definition | A non-fungible, yield-bearing token (ERC-1155 NFT) representing the coupon or interest portion of the RWA deposited. Each USI maps to a unique yield stream. |
| Standard | ERC-1155 with dynamic metadata. NFT-based design enables yield isolation, transferability (via OTC), and position-specific tracking of returns and maturity. |
| Accrual Mechanics | Yields accrue in real-time and are redistributed based on the fractional ownership of note positions in the Yield Pool. Coupon payments drive USI appreciation. |
| Usage | Held by minters to accumulate returns or transferred via whitelisted OTC deals. Required (with USP) to unlock principal on maturity or roll-over to new assets. |
| Yield Sources | IIAs, tokenized T-Bills, private credit, or other tokenized fixed income instruments. Yield is secured, predictable, and uncorrelated with crypto markets. |
| Secondary Market | Transferability restricted to approved entities and market makers. Prevents retail speculation while ensuring regulatory safety and managed circulation. |
| Governance Role | While USI has no governance power, it directly interacts with protocol flows that impact treasury yield and LP participation mechanics. |
| Capital Efficiency | By splitting the principal from yield, USI allows users to freely deploy USP for liquidity while still benefiting from yield — enabling layered compounding. |