31 CFR 501.603(a) and (b)(1): any U.S. person (or person subject to U.S. jurisdiction for the Cuba program), including financial institutions, holding blocked property must report it to OFAC through the OFAC Reporting System within 10 business days of blocking, giving the holder and contact, the transaction and participants, the sanctions target and its interest, the property and location, blocking date, U.S. dollar value, action taken (such as a labelled interest-bearing blocked account), the specific legal authority (not just 'SDN') and copies of payment and trade documents; primary responsibility rests with the actual holder.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.