Prosecutors were not able to obtain confidential data from corporations without first receiving written approval from the department.
keep sth/remain confidential »The bill would allow a business to keep its dealings confidential.
»The company's former employees had made improper use of highly confidential information, such as names and addresses of customers.
»All the employee questionnaires will be treated as strictly confidential.
»confidential advice
»The letter was marked ""confidential"".
Members of a client's workforce can discuss confidentially the reason for their absence, be it a mental or medical problem.
to speak confidentially to smb. - говорить с кем-л. по секрету
конфиденциально, по секрету
to speak ~ to smb. - говорить с кем-л. по секрету
конфіденційно, по секрету