OFAC FAQ #294 · Iran Sanctions
How will I know if someone is part of Iran’s energy, shipping, or shipbuilding sectors or is a port operator in Iran?
OFAC's answer
Persons determined to be part of Iran’s energy, shipping, or shipbuilding sectors, or a port operator in Iran for purposes of [IFCA](https://ofac.treasury.gov/media/5746/download?inline) section 1244(c) will be identified as such on the [SDN List](https://ofac.treasury.gov/specially-designated-nationals-list-data-formats-data-schemas). Knowingly providing certain significant support to persons determined to be part of Iran’s energy, shipping, or shipbuilding sectors, or a port operator in Iran will have exposure to sanctions, unless the transaction is excepted (see also Q&A [297](https://ofac.treasury.gov/faqs/297)).