According to "Yoro ritsuryo code" (code promulgated in the Yoro era), "shitokan" (four classifications of bureaucrats' ranks), including "Tenyaku no kami" (the head of Tenyakuryo), were established within Tenyakuryo, and there existed four kinds of technocrats, that is, doctor, acupuncturist, masseur, and necromancer.
養老律令によれば、典薬寮に典薬頭以下の四等官が設置され、医師・針師・按摩師・呪禁師の技術官僚が置かれた。