The Nirvana Sūtra, the “Four Reliances” chapter, preaches the “Four Reliances” in person and in dharma. The former is the four ranks of bodhisattvas upon whom Buddhists relied on for guidance after the death of the Buddha, and the latter is the four standards which Buddhists must follow: (1) to follow the true teaching, not persons; (2) to follow the meaning of the teaching, not the words; (3) to follow the wisdom of the Buddha, not the knowledge of the people; and (4) to follow the Lotus Sūtra, which is the true teaching, not the pre-Lotus sūtras. These are the basic teaching in practicing Buddhism.

Ichidai Goji Keizu, Genealogical Chart of the Buddha’s Lifetime Teachings in Five Periods, Writings of Nichiren Shōnin, Doctrine 3, Page 244