The affix ṇini comes in the sense of 'enounced by him' after the words 1. pārāśarya and 2. śilālin , the works enounced being bhikṣu-sūtra and naṭa-sūtra respectively.,
The affix णिनि is to be read into the sutra and not ढिनुक् ॥ The भिक्षुसूत्र and नटसूत्र are works treating of the duties of भिक्षुक 'religious mendicants' and नट 'jugglers, dancers'.
Thus पाराशर्य + णिनि = पाराशर + णिनि 6.4.152 = पाराशरिन्, 'the treatise of Parasarya on the duties of Bhikshus'. Similarly शैलालिन् ॥ These words, of course, have the additional sense of 'he who studies the works so enounced by Parasarya and Sailalin'. See 4.2.66. As पाराशरिणो भिक्षवः, शैलालिनो नटाः ॥ According to some, it always expresses this relation (तद्विषयता 4.2.66) and never a प्रोक्त alone. These are treated metaphorically as Chhandas.
Why do we say 'denoting Bhikshu and Nata Sutras'? Observe पाराशरम्, शैलालम् ॥,