U+10D21 Hanifi Rohingya Vowel O

The Wikipedia has the following information about this codepoint:

The Hanifi Rohingya script is a unified script for the Rohingya language. Rohingya today is written in three scripts, Hanifi, Arabic (Rohingya Fonna), and Latin (Rohingyalish). The Rohingya language was first written in the 19th century with a version of the Perso-Arabic script. In 1975, an orthographic Arabic script was developed and approved by the community leaders, based on the Urdu alphabet but with unique innovations to make the script suitable to Rohingya.

In the 1980s, Mohammad Hanif and his colleagues created a suitable phonetic script based on the Arabic alphabet; it has been compared to the N’ko script.

This script, unlike the Arabic script, is alphabetical, meaning that all vowels are independent letters, as opposed to diacritics as is the case in Arabic. However, vowels cannot stand on their own and always need to be connected to a consonant similar to diacritics. Therefore, diphthongs cannot be written as vowel-vowel combination even though typographically this is possible. Tone markers are shown as diacritics in Hanifi script. It is written from right to left, following the direction of the Arabic script.