Kinsho-tekken (Golden Railway Ticket)

…It was one shaku high and two shaku wide, with the history and achievements of the nobleman written in gold on the front (convex) side, and the degree of pardon and reduction in salary for the nobleman and his descendants when they committed crimes written in gold on the back (concave) side. This is why it was called the gold certificate or the gold-written iron certificate. It is said that when Emperor Gaozu of the Han Dynasty bestowed titles on nobles, he used iron certificates written in red ink, but later they began to be inlaid with gold. …

*Some of the terminology used in reference to "Kinshotetsuken" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…高さ1尺，幅2尺で，表(凸)面には功臣の履歴･功績が，裏(凹)面には功臣本人と子孫が罪過を犯した際の免罪と減俸の程度が金で書き込まれた。金券，金書鉄券といわれるゆえんである。漢の高祖が功臣を封じた際には丹書した鉄券を用いたとされるが，のち金を嵌入するようになった。…

※「金書鉄券」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報