kana writing style before switching to conventional sōrō-style Written Japanese as a result of the conquest by Satsuma Domain in 1609. Kanji logographs assigned to Okinawa have changed over time. Following the conquest in 1609, Satsuma conducted land surveys, gradually standardizing Kanji assigned to Okinawan toponyms. A common spelling before and immediately after the conquest was the inauspicious-looking 悪鬼納 (the first two characters mean evil demon), but Satsuma started using the current spelling 沖縄 as early as the 1620s. This spelling was popularized in mainland Japan by the Nantōshi (1719). Its author Arai Hakuseki was likely to have consulted a map of Okinawa Island submitted to the Tokugawa Shogunate by Satsuma Domain in 1702. The Shuri-Naha Okinawan form of Okinawa is ʔucinaa. The raising of the vowel /o/ to /u/ was a pan-Ryukyuan areal phenomenon while the palatalization of /k/ to /c/ [tɕ] before /i/ was a relatively recent change with a much geographically limited distribution. Most Northern Okinawan varieties resist this change. Even among South-Central varieties, Itoman, Komesu, Ōyama, and Tsuken Island varieties remain unaffected. For its conservativeness, the Standard Japanese form is effectively undoing historical sound changes. Okinawa Islands Adopting Western practices, the Japanese government started naming large groups of islands in the early Meiji period. The Nantō Suiro-shi (1873), the first coast pilot of the Nansei Islands published by the Hydrographic Office of the Imperial Japanese Navy, is credited for coining the name Okinawa Shotō (沖縄諸島, literally, Okinawa Islands). Its author, Captain Yanagi Narayoshi, initially consulted the British China Pilot forth edition (1864). Dissatisfied with a mixture of European, Chinese, and Japanese names in the European charts, he decided to give Japanese names to Japanese islands. According to Yanagi's classification, the Okinawa Shotō had smaller geographical extents than the modern Okinawa Islands as the Okinawa Shotō, the Kerama Shotō, and the Iheya Shotō constituted the Ryūkyū Guntō (literally, Ryūkyū Group). The name of Ryūkyū Guntō was replaced by Okinawa Guntō (沖縄群島) in 1883, and thereafter, the name of Okinawa Guntō has been used without interruption by the Hydrographic Office of the Imperial Japanese Navy and its successor, the Hydrographic and Oceanographic Department of the Japan Coast Guard. The Hydrographic and Oceanographic Department of the Japan Coast Guard is not the sole government organ that defines official geographical names of Japan. The Geospatial Information Authority of Japan (GSI), a subsidiary agency of the Ministry of Land, Infrastructure, Transport