udghātyakaḥ kathodghātaḥ prayogātiśayas tathā pravartakāvalagite pañca prastāvanā-bhidāḥ

Introductions may be classified as follows: (1) udghatyaka, (2) kathodghata, (3) prayogatisaya, (4) pravartaka and (5) avalagita. These five kinds of introduction are called amukha. Thus Srila Ramananda Raya asked which of the five introductions had been employed, and Srila Rupa Gosvami replied that he had used the introduction called the pravartaka.