i is substituted for the ī of bhī before a sārvadhātuka affix beginning with a consonant and having an indicatory k or ṅ,
Thus बिभितः or बिभीतः, बिभिथः or बिभीथः, बिभिवः or बिभीवः, बिभिमः or बिभीमः ॥ But बिभ्यति before a vowel-beginning affix and बिभेति before a non-ङित् affix and भीयते before an ardhadhatuka affix.,