The three kinds of practice

To accept, uphold, read, recite, take delight in, and protect all the eight volumes and twenty-eight chapters of the Lotus Sutra is called the comprehensive practice. To accept, uphold, and protect the "Expedient Means" chapter and the "Life Span" chapter is called the abbreviated practice. And simply to chant one four-phrase verse or the daimoku, and to protect those who do so, is called the essential practice. Hence, among these three kinds of practice, comprehensive, abbreviated, and essential, the daimoku is defined as the essential practice. 27/5

The Writings of Nichiren Daishonin
The Daimoku of the Lotus Sutra
Recipient unknown; written on January 6, 1266