Avestan Uu 𐬏

This letter writes the long close back u and closes the vowel section of the alphabet. After it the consonants begin, and the shape of the sequence, vowels first and in pairs, has by then been stated eight times over. Every vowel in this alphabet is a letter in its own right, standing on the line and taking its turn between the consonants. That is not how the writing it grew out of worked, where a reader supplied much of the vowelling from knowledge of the word, and it is not how the Indic scripts of the same centuries worked either, where vowels hung as marks above and below a consonant sign.

Avestan writes them out. It stands sixteenth in the alphabet as a whole and sixteenth of the sixteen vowel letters, between Avestan U and Avestan Ke. The order is the work of the people who devised the alphabet rather than an inheritance from anywhere, and reading the list straight through recovers the analysis they were working from. Comparison makes the point quickly. Book Pahlavi, the hand this alphabet was drawn from, had let so many sounds converge on shared shapes that reading it depends heavily on already knowing the word. The Avestan alphabet takes that apart and assigns one sign to each sound, which is why it needs fifty-four of them.

With this letter the vowel section closes, sixteen signs deep. No script in the region at the time carried a vowel inventory of that size, and none of its neighbours had the same reason to want one. Book Pahlavi is the hand behind these letterforms, and the relationship between the two is one of correction. In that writing a number of originally distinct sounds had come to share a single shape, so reading it depends on recognising words rather than on assembling them from letters.

The Avestan alphabet takes the same pen strokes and separates what had merged. Because the surviving copies are late, the evidence for what any individual letter did rests on the consistency of the manuscript tradition rather than on early witnesses. Where the copies agree, editors follow them; where they do not, the disagreement is recorded rather than settled by preference. In the digital record the letter is encoded at U+10B0F AVESTAN LETTER UU. The whole Avestan block lies above the Basic Multilingual Plane, so each character needs a surrogate pair in the encodings that use them, and a font carrying the script is required before anything appears on a screen at all. For the community the value of a script that writes every sound is continuity. It makes it possible to check a recitation against a page rather than against another reciter's memory, which is what the alphabet was for and what it still does.