A shabnama (Persian: شبنامه, 'night letter') is a pamphlet communicating warnings or direction, which are surreptitiously distributed.
Shabnama have been found throughout Iranian history. An early 20th century example would be following the Persian Constitutional Revolution, when shabnameh were distributed in Tehran decrying the occupation of parts of Iranian territory by Russian troops, and against the changing of the legal examination laws.
References
Shabnameh Wikipedia(Text) CC BY-SA