 The notational system introduces different clusters of phonemes that serve special roles in the morphology of Sanskrit, and are referred to throughout the text.Each cluster, called a "pratyāhara" ends with a dummy sound called an "anubandha" (the so-called "IT" index), which acts as a symbolic referent for the list.Within the main text, these clusters, referred through the anubandhas, are related to various grammatical functions.