And in the Tang Dynasty, 'Kugen' (official documents authorized by Kokushi (provincial governors) or Gunji (local magistrates) for transfer of the ownership of private property existed as an official document similar to Kasho, and was called 'Kubyo' or 'Inkyo' in the late age of the Sung dynasty.
また、唐代には、過所に類した公文書として「公験」があり、宋(王朝)代の後半には「公憑」や「引拠」と呼ばれた。