(ilhas, plural). The term os Lequeos can be found in Vasco Calvo's letter (circa 1536). In Portuguese (and in English), a definite article plus the plural form of a toponym can refer to a group of islands, a construction that has no equivalent in East Asian languages. The so-called Biblioteca Vallicelliana map (circa 1550) was the first map that shows the label Ryūkyū. Reflecting Ming Chinese terminology, the map depicts a chain of islands in which the captions lequio menor (Little Ryūkyū, i.e., Taiwan), lequio maior (Great Ryūkyū, i.e., Okinawa Island), and japan are given from the southwest to the northeast. A large caption LEQVIOS is attached to the island chain. The combination of the three names can be found in a report written by the Spanish monk Martín de Rada in the 1570s: leuqiu el menor, leuqiu el grande, and los lequios (plural). Adopting Western practices, Japanese technocrats and academicians chose the Sino-Japanese term shotō (諸島) to explicitly mark the plurality of islands. A related term guntō (群島) was used in place of English group. The Japanese government assigned hierarchically organized names to the southwestern islands of Japan. These names had been standardized toward the end of the 19th century. The top-level entity that covers the (nearly) entire island chain between Kyushu and Taiwan is the Nansei Shotō (南西諸島, literally, Southwestern Islands). For the subgroups of the Nansei Shotō, however, there remained disagreements between the Hydrographic and Oceanographic Department of the Japan Coast Guard and the Geospatial Information Authority of Japan (GSI). The former provided a flatter organization: Nansei Shotō (南西諸島) Ōsumi Guntō (大隅群島) Tokara Rettō (吐噶喇列島) Amami Guntō, (奄美群島), which include Iōtorishima Okinawa Guntō (沖縄群島) Sakishima Shotō, (先島諸島) which covers the Senkaku Islands Daitō Shotō (大東諸島) On the other hand, the GSI defined a deeper hierarchy: Nansei Shotō (南西諸島) Satsunan Shotō (薩南諸島) Ōsumi Guntō (大隅諸島) Tokara Rettō (吐噶喇列島) Amami Shotō (奄美諸島) Ryūkyū Shotō (琉球諸島) Iōtorishima Okinawa Shotō (沖縄諸島) Sakishima Shotō, (先島諸島) Senkaku Shotō (尖閣諸島) According to the GSI's definition, the Ryūkyū Shotō covers Okinawa Prefecture except the outlying Daitō Islands. The two government organs have worked on resolving disagreements. As a result, the Satsunan Shotō and Ryūkyū Shotō among many others are recognized as the standard geographical names of Japan. As a member of the International Hydrographic Organization, Japan uses these geographical names for the International (INT) Charts it produces. The name of the Ryukyu Islands became a