Beneficial owner. For payments other than those for which a reduced rate of
withholding is claimed under an income tax treaty, the beneficial owner of income is
generally the person who is required under U.S. tax principles to include the income
in gross income on a tax return. A person is not a beneficial owner of income,
however, to the extent that person is receiving the income as a nominee, agent, or
custodian, or to the extent the person is a conduit whose participation in a
transaction is disregarded. In the case of amounts paid that do not constitute income,
beneficial ownership is determined as if the payment were income.

这是关于美国税法的一个问题。译文：

受益所有人（也可译作实益拥有人）是指那些获得支付，但不包括在根据所得税协议可获低税率扣减所得税的人。收入的受益所有人通常应按美国的税法在报税时将这部分收入计入总收入。然而，下列人士不视为受益所有人：作为受托人，代理人或监护人而得到收入；作为传输者，他们的参与在交易中可忽略不计。在某些已支付的款项没有构成收入的情况下，支付给受益所有人的部分应确定视为收入。