In national or subnational freedom of information policies, governments are often required to tell people who request information (e.g. journalists or attorneys) whether they located the requested records, even if the records end up being kept secret. But at times, a government may determine that the mere act of truthfully disclosing that the records do or do not exist would pose some actual or possible harm, such as to national security, the integrity of an ongoing investigation, or a person's privacy. For example, disclosing that a police department has documents about a current investigation into a criminal conspiracy, even if the content of the documents is not disclosed, would make it public that the investigation is happening and could help suspects destroy evidence.
