niepisanym
Niepisanym is the instrumental singular form of the Polish adjective niepisany, meaning unwritten or not written down. The term is used to describe norms, laws, or conventions that are observed as informal or customary rather than codified in statutes or formal documents. It is common in legal, sociological, cultural discourse and in everyday speech to contrast formal, written rules with informal expectations.
In usage, niepisany conveys tacit knowledge or customary practice, rather than something established by written rules.
Etymology: it is built from the negation prefix nie- and pisany (written). The composite reflects the distinction
See also: unwritten law, unwritten rule, unwritten tradition.