History and Teachings of Nichiren Buddhism, p 119-120[The distinct doctrine] explains the doctrine that transcends the triple world and belongs to the bodhisattvas alone, as outlined in the following eight categories: teaching, principle, wisdom, cutting off defilements, practices, stages, causes, and attainment. This is distinct from the two previous doctrines, tripiṭaka and common, and is distinct from the perfect doctrine that follows. Therefore, it is called distinct.
This doctrine is taught to bodhisattvas only. Dharma is equal for all people. However, as each phenomenon in nature is as distinct as each person’s perception of it, so this distinct doctrine is distinct from the tripiṭaka, the common doctrine, and the perfect doctrine. The purpose of the tripiṭaka and common doctrines is relief from the sufferings of birth and death within the triple world. In the distinct doctrine, suchness and ignorance are taught because delusions exist beyond the phenomenal world.
The distinct doctrine teaches the three truths of emptiness, provisional existence and the middle, independently from one another. In other words, practitioners understand the middle way by contemplating the three truths, but they observe the middle way separately from emptiness and provisionality. Thus it is called “only the middle, independent of others.” Bodhisattvas in the stage of the distinct doctrine observe emptiness, provisionality, and the middle way one by one; cut off the three categories of delusion; obtain the three kinds of wisdom simultaneously; partially cut off delusion by practicing for themselves and others; and benefit others according to their karma.