A long time ago, someone decided that if your file was 100% ASCII and you chose to save it as UTF-8 and you opened the file up again and added some >0x007f char

A long time ago, someone decided that if your file was 100% ASCII and you chose to save it as UTF-8 and you opened the file up again and added some >0x007f character and later saved again that you should not be prompted The author makes this sound like an unreasonable request, but I don't see the problem. All ASCII text is also UTF-8; if a file is valid ASCII, it should be opened and saved in UTF-8 mode. P.S. Isn't there some tool on UNIX that does this correctly? Yes, nearly all of them.