As a side effect of its development, the script was also used for Pazend, a method of writing Middle Persian that was used primarily for Zend commentaries on the texts of the Avesta.

The various text collections that today constitute the canon of Zoroastrian scripture are the result of a collation that occurred in the 4th century, probably during the reign of Shapur II (309–379).

The enterprise, "which is indicative of a Mazdean revival and of the establishment of a strict orthodoxy closely connected with the political power, was probably caused by the desire to compete more effectively with Buddhists, Christians, and Manicheans, whose faith was based on a revealed book".

The question of the existence of a pre-Sassanid "Arsacid archetype" occupied Avestan scholars for much of the 19th century, and, "[w]hatever may be the truth about the Arsacid Avesta, the linguistic evidence shows that even if it did exist, it can not have had any practical influence, since no linguistic form in the Vulgate can be explained with certainty as resulting from wrong transcription and the number of doubtful cases is minimal; in fact it is being steadily reduced.

In contrast, Avestan was a full alphabet, with explicit characters for vowels, and allowed for phonetic disambiguation of allophones.

There are two main transcription schemes for Avestan, the newer orthography used by Karl Hoffmann and the older one used by Christian Bartholomae.

Later, when writing Middle Persian in the script (i.e. Pazend), another consonant 𐬮 was added to represent the /l/ phoneme that didn't exist in the Avestan language.