Izhitsa answers to Greek upsilon and closes the Glagolitic alphabet in the traditional order. It carries no numeral value in this script, standing well past the end of the counted series, although the corresponding Cyrillic letter takes four hundred from the Greek value.
Like fita it exists for Greek rather than for Slavonic. It appears in words and names borrowed from Greek and is read as i or as v depending on the letters around it, following the Greek pronunciation of the period rather than any Slavonic rule. Its presence in a word is a reliable indication that the word came in with the scriptures and the liturgy.
Its name is unusual among the letter names of the alphabet. It is a diminutive built on the name of the letter izhe, so it means something like the small izhe, which makes it one of the very few Slavonic letter names derived from another Slavonic letter name rather than from a Slavonic word or from a Greek name. That derivation is transparent, unlike the names of most of the letters around it.
The letter closes both the abecedaria and the recitation.
Its position at the very end, after the letter for Greek theta, follows the same principle: the Greek letters that Slavonic needs only for Greek words come last, after the Slavic signs, where they can be learned last and used least. Both Slavonic alphabets arrange the tail of the order that way, which is one more of the structural agreements between them.