NSF21FunctionKey The F21 key. Declarationvar NSF21FunctionKey: Int { get } DiscussionThis key is unavailable on most Macintosh keyboards. See AlsoGetting the Function KeysNSF1FunctionKeyNSF2FunctionKeyNSF3FunctionKeyNSF4FunctionKeyNSF5FunctionKeyNSF6FunctionKeyNSF7FunctionKeyNSF8FunctionKeyNSF9FunctionKeyNSF10FunctionKeyNSF11FunctionKeyNSF12FunctionKeyNSF13FunctionKeyNSF14FunctionKeyNSF15FunctionKey