confidentiel ☊ 
confidential like: confidential → →
to report secretly; confidential report ☊ 
mật báo ☊ secret decree, secret order, confidential order ☊ mật dụ ☊ access to confidential information ☊ access ☊
file on sb: to have/open/keep a confidential file on sb ☊ file ☊
I would be most grateful if you would keep this matter confidential. ☊ grateful ☊
Do not open any mail marked 'Confidential'. ☊ mark ☊
stress that...: I must stress that everything I've told you is strictly confidential. ☊ stress ☊
My letter is, of course, strictly private and confidential. ☊ strictly ☊
confidentiel ☊ soyez attentif, ce message est confidentiel ☊