Hi all, I have a problem that I cannot understand! According to the documentation, there is a method "mutableString" which, in the NSMutableAttributedString class So, with this code Code: NSMutableString * s = [_mString mutableString]; I would have expected s to be a mutableString. Here is the error: Changing to this code: Code: NSString * s = [_mString string]; eliminates this issue...but the question is why? The literature that I have looked at does not seem to have an answer. Thanks as usual.