1.1.49 स्थाने अन्तर्तमः

A very important rule in sutras that implies that अन्तर्तम occurs at the स्थान i.e. the class in षष्ठी of the particular rule ( according 1.1.48). अन्तर्तम itself is of the following priority : 
1. अर्थ 

2. स्थान 

3. प्रयत्न 

4. मात्रा