A page from Tự Đức Thánh Chế Tự Học Giải Nghĩa Ca (嗣德聖製字學解義歌), a 19th-century primer for teaching Vietnamese children Chinese characters. The work is attributed to Emperor Tự Đức, the 4th Emperor of the Nguyễn dynasty. In this primer, chữ Nôm is used to gloss the Chinese characters, for example, 𡗶 is used to gloss 天.