the seal in the recommendation letter of the graduate school supervisor is the seal of the college and the seal of the academic affairs department of the school. Bao Yan is a letter of recommendation written in the name of the tutor, with the signature and seal of the recommender. Generally, it is necessary for the academic affairs office of the college to issue the seal of the college and the seal of the academic affairs office of the school to be effective. Therefore, the seal in the recommendation letter of the graduate school supervisor is the seal of the college and the seal of the academic affairs department of the school.