The affix ṭhañ comes after a word being the name of sacrifice, in the sense of 'the fee thereof'.,
As अग्निष्टोमस्य दक्षिणा = आग्निष्टोमिकी, वाजपेयिकी, राजसूयिकी ॥
The word आख्या in the sutra implies that the affix comes even after those sacrifice-denoting words which do not express time 5.1.78; had it not been used, the sutra would have applied only to such sacrifice-denoting words as एकाहः, द्वादशाह, which are time-denoting words as well. The Vartika in 5.1.20 would apply to द्वादशाह &c. Some texts do not read च in the sutra.,