Editing Idu script (section)

{{Short description|Archaic Korean language writing system}}
{{About|an archaic writing system of Korea|the ethnic group in Tibet|Lhoba people}}
{{Infobox Korean name
|img=Yuseopilji.jpg
|caption=A page from the 19th-century yuseopilji.
|hangul=이두
|hanja={{linktext|吏|讀|}}
|rr=Idu
|mr=Idu
}}
{{Korean writing}}
{{Table Hanzi}}

'''Idu''' ({{Korean|hangul=이두|hanja=吏讀|lit='official's reading'}}) was a [[writing system]] developed during the [[Three Kingdoms of Korea|Three Kingdoms]] period of Korea (57 BC-668 AD) to write the [[Korean language]] using [[Chinese characters]] ("[[hanja]]"). It used Hanja to represent both native Korean words and grammatical morphemes as well as Chinese loanwords. The script, which was developed by Buddhist monks, made it possible to record Korean words through their equivalent meaning or sound in Chinese. It was used primarily to write official documents and the [[imperial examinations]] from 958 AD-1894 AD.<ref>{{Cite book |title=The Origins of Higher Learning: Knowledge Networks and the Early Development of Universities |last1=Lowe |first1=Roy |last2=Yasuhara |first2=Yoshihito |date=2016 |publisher=Taylor & Francis |isbn=978-1-138-84482-7 |location=Oxon |page=80 |name-list-style=amp}}</ref>

The term ''idu'' may refer to various systems of representing [[Korean phonology]] through hanja, which were used from the early [[Three Kingdoms of Korea|Three Kingdoms]] to [[Joseon]] periods. In this sense, it includes ''[[hyangchal]]'',<ref name=Oxford>{{Cite book |title=The Oxford Handbook of Sound and Imagination |last1=Grimshaw-Aagaard |first1=Mark |last2=Walther-Hansen |first2=Mads |last3=Knakkergaard |first3=Martin |date=2019 |publisher=Oxford University Press |isbn=978-0-19-046016-7 |location=New York |page=426 |name-list-style=amp}}</ref> the local writing system used to write vernacular poetry<ref name=Oxford /> and ''[[gugyeol]]'' writing. Its narrow sense only refers to ''idu'' proper<ref>{{Cite book |url=https://books.google.com/books?id=Jvm7DwAAQBAJ&q=idu+script+hanja&pg=PT120 |title=The Chinese Writing System in Asia: An Interdisciplinary Perspective |last=Li |first=Yu |date=2019-11-04 |publisher=Routledge |isbn=978-1-00-069906-7 |language=en}}</ref> or the system developed in the [[Goryeo]] (918–1392), and first referred to by name in the ''[[Jewang ungi]]''.