This also affects any characters you type using the Option or Control keys (like a bullet - Option-8). Note that the period before the three character extension (.mp3, .aac, .jpg) is not considered as part of the file name in this case. This doesn't affect audio files you copy inside of iTunes.
If you copy a file that contains such a character in its name to iPod shuffle from a Mac, you will see a message that says one or more files could not be copied. If you ignore this message and then transfer the files from iPod shuffle to another computer, the filenames may not appear as they did on the original computer.
Does this mean you have to rename every file that contains these special characters you want to copy to iPod shuffle? Not at all. Just follow these steps to create an archive file that acts as an envelope for your other files, allowing you to keep your original file names intact. If you already tried copying the files separately, remove them from iPod shuffle first.
Mac OS X 10.3 or later
If you're not running Mac OS X 10.3, you can use an archive program such as Stuffit or Zip to create an archive, or rename your files without using any special characters.
Important: Information about products not manufactured by Apple is provided for information purposes only and does not constitute Apple's recommendation or endorsement. Please contact the vendor for additional information.