Surname law matronym from the name of a parent or parent-in-law; these possibilities are not necessarily open to native Icelanders. Reza Shah Pahlavi ordered Iranians to adopt Western style surnames in place of old Islamic names and titles during his reign. A law in Japan dating from 1896 requires a married couple to have a common surname. Most commonly it was the wife who took her husband's name. In 2011, this law was challenged as unconstitutional on gender equality grounds, but the Supreme Court of Japan upheld the law in 2015. Prussia tasked the implementation of surnames to E. T. A. Hoffmann.
Double-barrelled name at the end, regardless of whether that name has been passed down by the father or mother, or adopted through marriage. Unlike in the Russian or Hispanic systems, this surname-style middle name is not considered a proper last name in official documents, unless hyphenated into one compound name. In Poland a double surname () is generally joined with a hyphen and by law includes only one hyphen. Polish surnames ("nazwisko" (N. sg.)), like those in most of Europe, are hereditary and generally patrilineal, i.e., passed from the father on to his children. A married woman usually adopts her husband's name.