Secrecy is the practice of hiding information from certain individuals or groups who do not have the "need to know", perhaps while sharing it with other individuals. That which is kept hidden is known as the secret.
Secrecy is often controversial, depending on the content or nature of the secret, the group or people keeping the secret, and the motivation for secrecy.
A cabal is a group of people who are united in some close design, usually to promote their private views or interests in an ideology, a state, or another community, often by intrigue and usually without the knowledge of those who are outside their group. The use of this term usually carries negative connotations of political purpose, conspiracy and secrecy. It can also refer to a secret plot or a clique, or it may be used as a verb (to form a cabal or secretly conspire).
In communications and information processing, code is a system of rules to convert information—such as a letter, word, sound, image, or gesture—into another form, sometimes shortened or secret, for communication through a communication channel or storage in a storage medium. An early example is an invention of language, which enabled a person, through speech, to communicate what they thought, saw, heard, or felt to others. But speech limits the range of communication to the distance a voice can carry and limits the audience to those present when the speech is uttered. The invention of writing, which converted spoken language into visual symbols, extended the range of communication across space and time.
The process of encoding converts information from a source into symbols for communication or storage. Decoding is the reverse process, converting code symbols back into a form that the recipient understands, such as English, Spanish, etc.
A black market is a clandestine market or series of transactions that has some aspect of illegality, or is not compliant with an institutional set of rules. If the rule defines the set of goods and services whose production and distribution are prohibited or restricted by law, non-compliance with the rule constitutes a black-market trade since the transaction itself is illegal. Such transactions include the illegal drug trade, prostitution (where prohibited), illegal currency transactions, and human trafficking.
Participants often conceal illegal behavior from government authorities or regulators. Cash remains the preferred medium of exchange for illegal transactions, as it is more difficult to trace. Common reasons for engaging in black market activity include trading contraband, avoiding taxes or regulations, or evading price controls and rationing. Such activities are generally referred to using the definite article, e.g., "the black market in bush meat".
Open government is the governing doctrine which maintains that citizens have the right to access the documents and proceedings of the government to allow for effective public oversight. In its broadest construction, it opposes reason of state and other considerations which have tended to legitimize extensive state secrecy. The origins of open-government arguments can be dated to the time of the European Age of Enlightenment, when philosophers debated the proper construction of a then nascent democratic society. It is also increasingly being associated with the concept of democratic reform. The United Nations' Sustainable Development Goal 16, for example, advocates for public access to information as a criterion for ensuring accountable and inclusive institutions.
Redaction or sanitization is the process of removing sensitive information from a document so that it may be distributed to a broader audience. It is intended to allow the selective disclosure of information. Typically, the result is a document that is suitable for publication or for dissemination to others rather than the intended audience of the original document.
When the intent is secrecy protection, such as in dealing with classified information, redaction attempts to reduce the document's classification level, possibly yielding an unclassified document. When the intent is privacy protection, it is often called data anonymization. Originally, the term sanitization was applied to printed documents; it has since been extended to apply to computer files and the problem of data remanence.