Yo was the financial resources used for covering the expenditure on food given to Eji (a guard) and Uneme (a court lady), as well as the expenditure on wages and food given to Koekimin (drafted workers under the Ritsuryo system) engaging in public utilities.
庸は、衛士や采女の食糧や公共事業の雇役民への賃金・食糧に用いる財源となった。