Rasarnavasudhakara 3.507

3.507

prahasanasya śuddhādi-bhedāḥ-
śuddhaṃ kīrṇaṃ vaikṛtaṃ ca tac ca prahasanaṃ tridhā |
śuddhaṃ śrotriya-śākhāder veṣa-bhāṣādi-saṃyutam ||

The varieties of prahasana, such as pure:
And that prahasana is threefold: pure (śuddha), mixed (kīrṇa), and altered (vaikṛta). / The pure is furnished with the dress, speech, and so on of Vedic scholars and their associates,