Bidirectional Class - Arabic Letter

Arabic Letter is a bidirectional class value that marks characters which are inherently written from right to left, such as the letters of the Arabic alphabet and similar scripts like Hebrew and Syriac. When a text contains these characters, the Unicode bidirectional algorithm uses this class to establish the correct base direction for surrounding neutral characters, ensuring that punctuation and numbers are placed appropriately in mixed-direction contexts. This class is distinct from other right-to-left types, like Arabic Number or European Number, because it applies specifically to letters and not digits or symbols, and it influences how runs of text are ordered and how adjacent weak or neutral characters inherit directionality relative to the strong directionality of these letters.