In April 1438, Nam Hoi and Jo Min were appointed "Muleungdo Inspectors" and sent to Muleungdo bring back people hinding on the island. They ended up bringing back sixty-six people and some products from the island. The following record describes their return.
Notice that the above record mentions only Muleungdo, not Usando. Their description of the island fits that of the main island of Ulleungdo, so again, Muleungdo is either referring to the main island or to the island group, in general, not to any neighboring islands.
Source:『世宗實錄』 卷 八十二, 世宗 二十年 七月 戊戌條
July 15, 1438
護軍南薈司直曹敏 回自茂陵島復命 進所捕男婦共六十六及産出沙鐵石鍾乳生鮑大竹等物 仍啓曰 發船一日一夜乃至 日未明 掩襲人家 無有拒者 皆本國人也 自言聞此地沃饒 年前春 潛逃而來 其島四面皆石雜木與竹成林 西面一處可泊舟楫 東西一日程 南北一日半程
호군(護軍) 남회(南薈)와 사직(司直) 조민(曹敏)이 무릉도(茂陵島)로부터 돌아와 복명하고, 포획한 남녀 모두 66명과 거기서 산출되는 사철(沙鐵) 석종유(石鍾乳) 생포(生鮑) 대죽(大竹) 등의 산물을 바치고, 인하여 아뢰기를, “발선(發船)한 지 하루 낮과 하루 밤 만에 비로소 도착하여 날이 밝기 전에 인가를 엄습(掩襲)하온즉, 항거하는 자가 없었고, 모두가 본국 사람이었으며, 스스로 말하기를, 이곳 토지가 비옥하고 풍요하다는 말을 듣고 몇 년 전 봄에 몰래 도망해 들어왔다고 하였습니다. 그 섬은 사면이 모두 돌로 되어 있고, 잡목과 대나무가 숲을 이루고 있었으며, 서쪽 한 곳에 배를 정박시킬 수 있고, 동서는 하루의 노정(路程)이고 남북은 하루 반의 노정이었습니다” 라고 하였다.
Hogun Nam Hoi and Sajik Jo Min returned from Muleungdo and reported that they captured a total of sixty-six men and women and that they brought back such products as lodestone, stalactite, and abalone as tribute.
They said, "We arrived after only one day and one night at sea. Before daybreak we conducted a surprise raid on the households there, who surrendered without any resistance. All were people of our country. They said they had secretly gone to the island in the spring a few years before after hearing that the land was fertile and bountiful. All four sides of the island is made up of rock, and the forrest is made up of various trees and large bamboo. On the west side there is a place to anchor boats. It takes one day to travel the island (on foot) from east to west and a day and a half to travel it from north to south."