Need to know
The term "need to know" (alternatively spelled need-to-know), when used by governments and other organizations (particularly those related to military or intelligence), describes the restriction of data which is considered very confidential and sensitive. Under need-to-know restrictions, even if one has all the necessary official approvals (such as a security clearance) to access certain information, one would not be given access to such information, or read into a clandestine operation, unless one has a specific need to know; that is, access to the information must be necessary for one to conduct one's official duties.