Filing A · final
The original synthetic filing remains sealed, readable and verifiable.
Original remains intact · amendment becomes new final state
An amended return should not erase the return it amended.
Filing B · derived
A new UDR cites Filing A as parent and records the supplied amendment reason.
Compare
Changed blocks and supporting-reference changes are visible before finalization.
Filing B · final
The amended UDS records supersession while preserving both final states.