Used in the context of securities, the illegal practice of a public offering participant keeping some shares in a private account or with a family member, employee, or dealer to profit from the higher market price of a hot issue. Used in the context of taxes, the withholding by an employer of a certain amount of an employee's income in order to cover the employee's tax liability. Also used to refer to the withholding by corporations and financial institutions of a flat 10% of interest and dividend payments due to security holders.