What's the noun for iota? Here's the word you're looking for.
iotation
(linguistics) A specific occurrence of palatalization that occurred in the Proto-Slavic language, in which a consonant combined with the palatal approximant /j/ to form a palatalized consonant.
(linguistics) Any similar process occurring in a later Slavic language or elsewhere.
iotacism
Pronunciation of another vowel or diphthong as [i], or a vowel shift resulting in such pronunciation, especially in Greek.