Rohingya language requirements for Arabic script

Rohingya can be written in four different scripts (Arabic, Hanifi Rohingya, Latin, and Myanmar). Fonts which are intended to support the Rohingya language using Arabic script must include some different lesser used characters as well as different design features than those designed for standard Arabic. In every case, the blue is what a Rohingya font should support.

Rohingya includes some special characters which are not used in any other known language. These are:

U+08AA ࢪ ARABIC LETTER REH WITH LOOP
U+08AB ࢫ ARABIC LETTER WAW WITH DOT WITHIN
U+08AC ࢬ ARABIC LETTER ROHINGYA YEH
U+08E4 ◌ࣤ ARABIC CURLY FATHA
U+08E5 ◌ࣥ ARABIC CURLY DAMMA
U+08E6 ◌ࣦ ARABIC CURLY KASRA
U+08E7 ◌ࣧ ARABIC CURLY FATHATAN
U+08E8 ◌ࣨ ARABIC CURLY DAMMATAN
U+08E9 ◌ࣩ ARABIC CURLY KASRATAN
U+08EA ◌࣪ ARABIC TONE ONE DOT ABOVE
U+08EB ◌࣫ ARABIC TONE TWO DOTS ABOVE
U+08EC ◌࣬ ARABIC TONE LOOP ABOVE
U+08ED ◌࣭ ARABIC TONE ONE DOT BELOW
U+08EE ◌࣮ ARABIC TONE TWO DOTS BELOW
U+08EF ◌࣯ ARABIC TONE LOOP BELOW

The first three characters in the above list are right-joining characters. Next, we have six vowel marks, followed by six tone marks. The vowel marks behave as other vowel marks in Arabic script. However, the tone marks will always appear following a vowel mark. If the vowel is an above mark, then the following tone must also be an above mark. If the vowel is a below mark, then the following tone must also be an above mark.

Rohingya tone.

When a kasra is used in context with the shadda, most Arabic fonts will move the kasra up and ligate it below the shadda. This should not happen for Rohingya support. The kasra should remain below the base.

Rohingya shadda-kasra in blue.

The Rohingya prefer a different style of dammatan.

Rohingya dammatan in blue.

Rohingya has a different style of digits for U+06F4 ۴ EXTENDED ARABIC-INDIC DIGIT FOUR, U+06F6 ۶ EXTENDED ARABIC-INDIC DIGIT SIX and U+06F7 ۷ EXTENDED ARABIC-INDIC DIGIT SEVEN.

Rohingya digits in blue.