Arabic letter mark


The Arabic letter mark is a non-printing character used in the computerized typesetting of bi-directional text containing mixed left-to-right scripts and right-to-left scripts.
Similar to Right-to-left mark, it is used to change the way adjacent characters are grouped with respect to text direction, with some difference on how it affects the bidirectional level resolutions for nearby characters.

Unicode

In Unicode, the ALM character is encoded at.
In UTF-8 it is. Usage is prescribed in the Unicode Bidirectional Algorithm.