TQString::fromUtf8 vs TQString::fromLatin1

Hi all, I need some help again. Which is the preferred function to use when creating TQString from std::string and how can I make sure that I end up with Utf-8. The thing is that input in std::string can be either UTF-8 or not UTF-8. What is the standard way of doing this in TDE (TQt)? I am really confused, because I was looking in some KDE3/TDE code and I see both used. My problem is that some older phones would most likely lack UTF and newer would do only UTF. So how can I make sure to "speak the right language" with them? A hint would be appreciated. regards