Succeeding Jogankyaku, Engikyaku is a selected collection of particularly important volumes which had been in actual effect at the time of its compilation out of Jogankyaku, so chosen as to comprise imperial edicts and Daijokanbu (official documents issued by Daijokan, the Grand Council of State) during the 39 years from 869 until 907, while its contents were classified by ministry.
「貞観格」を継いで貞観_(日本)11年（869年）より延喜7年（907年）までの39年間の詔勅・太政官符のうち編纂当時に実際に行われていた重要なものを取捨選択して各省毎に配列した。