U+FB66 "ﭦ" Arabic Letter Tteh Isolated Form Unicode Character

U+FB66 "ﭦ" Arabic Letter Tteh Isolated Form is a presentation form of the Arabic letter tteh, which represents a retroflex or emphatic "t" sound used in certain languages like Urdu, Sindhi, and Kashmiri. This specific codepoint belongs to the Arabic Presentation Forms-A block, where it serves as a positional variant intended for use when the letter appears alone at the beginning or within text where special typographic shaping is required. While modern Unicode typically prefers encoding the standard Arabic letter with a joining behavior class, this isolated form was included for backward compatibility with older software and document formats that rely on precomposed glyphs.