kCTTypesetterOptionForcedEmbeddingLevel
A key that specifies the embedding level of the typesetter’s text.
Declaration
let kCTTypesetterOptionForcedEmbeddingLevel: CFStringDiscussion
The value for this key must be a CFNumberRef object. There’s no default value.
Normally, typesetting applies the Unicode Bidirectional Algorithm as described in Unicode Standard Annex #9. If present, this option specifies the embedding level, and the text system ignores any directional control characters.