Following Enchin's return from China and his petition to the Imperial Court in 863 titled "Enchin's Request for a Kugen Certificate of Transmitting the Dharma," the Department of State issued a kugen certificate (proof) for transmitting the Dharma to Enchin in May of 866. The certificate quotes the entire text of Enchin's petition, officially acknowledging his achievements and results from his journey to seek the Dharma in China and approving the teaching of both the Shingon esoteric and Shikan (i.e., Tendai) exoteric schools of Buddhism. The latter part of this certificate in particular is almost identically quoted in Nihon Sandai Jitsuroku, one of the Six National Histories, making it a rare example of a historical document actually used to compile official histories.