This letter is no longer used in Persian, as the [β]-sound changed to [b], e.g. archaic زڤان /zaβɑn/ > زبان /zæbɒn/ 'language'.

The script is mostly but not exclusively right-to-left; mathematical expressions, numeric dates and numbers bearing units are embedded from left to right.

The Arabic alphabet was introduced to the Persian-speaking world after the Muslim conquest of Persia and the fall of the Sasanian Empire in the 7th century.

Today, extended versions of the Persian alphabet are used to write a wide variety of Indo-Iranian languages, including Kurdish, Balochi, Pashto, Urdu (from Classical Hindostani), Saraiki, Panjabi, Sindhi and Kashmiri.

In the past the use of the Persian alphabet was common amongst Turkic languages, but today is relegated to those spoken within Iran, such as Azerbaijani, Turkmen, Qashqai, Chaharmahali and Khalaj.

During the colonization of Central Asia, many languages in the Soviet Union, including Persian, were reformed by the government.

For clarification, they are often called hâ-ye jimi (literally "jim-like he" after jim, the name for the letter ج that uses the same base form) and hâ-ye do-češm (literally "two-eyed he", after the contextual middle letterform ـهـ), respectively.

There are eight Persian letters that are mainly used in Arabic or foreign loanwords and not in native words: ث, ح, ذ, ص, ض, ط, ظ, ع and غ.

The archaic letter ݿ /g/ was also used as a substitute for the twenty-sixth letter of the Persian alphabet, گ, which was used to appear in the older manuscripts of Persian in the late 18th century to the early 19th century.

The standard Arabic version ي يـ ـيـ ـي always has 2 dots below.

See Persian Phonology In Farsi, none of these short vowels may be the initial or final grapheme in an isolated word, although they may appear in the final position as an inflection, when the word is part of a noun group.

In a word that ends with a vowel, letters ع, ه and و respectively become the proxy letters for zebar, zir and piš, e.g. نو (now, meaning "new") or بسته (bast-e, meaning "package").

The Unicode Standard has a compatibility character defined U+FDFC ﷼ RIAL SIGN that can represent ریال, the Persian name of the currency of Iran.

All the digits also have different codepoints in Unicode:[13] sefr yek do se čahâr panj šeš haft hašt no Typically, words are separated from each other by a space.

As part of the russification of Central Asia, the Cyrillic script was introduced in the late 1930s.

[18][19][20][21][22][23][24][25][26][27][28][29][excessive citations] The Persian alphabet was introduced into education and public life, although the banning of the Islamic Renaissance Party in 1993 slowed adoption.

In 1999, the word Farsi was removed from the state-language law, reverting the name to simply Tajik.