The fact that it is often difficult to distinguish documents containing confidential information from documents that may be freely accessible to the public represents a particular problem. When we know that certain records contain confidential information, it is therefore sometimes necessary to introduce special procedures for entire archives or parts of archives, i.e. "restrict" this material.
In general, public archives are restricted for 60 years, due to provisions on duty of confidentiality in Norwegian Public Administration Act, Section 13 c. Most archives older than 60 years are accessible for use. But due to privacy rights, certain series are under restrictions for extended periods. This includes data such as confidential information from criminal cases, prison archives and health archives (80 years), and statistical base data containing personal information (100 years).
Not until someone is in need of using said material will resources be allocated, within reasonable limits, for an actual review of the relevant data. The evaluation prior to disclosure may entail a waiting period. Under certain specified conditions, users may gain access to restricted material; in some cases by submitting a written petition.