I have never had the entire tag as an alphanumeric string but there's a first time for everything. Some files downloaded from PCs only have a limited display space for the file tag and so they translate the long version into a shortened coded version which is what you see. Assuming that you have selected iTunes as the default format for your downloads from the internet, it is easy to drop into LW Library and change the tag by clicking on the words, waiting a moment and then clicking again. This will open the box for you to edit. When you have finished, press return to save the edit.

I have a routine of editing the tags immediately the download is completed. That way, I never lose track of what each file is. And you always know when the download has been brought to to successful conclusion because it tells you when the file is "Complete" in the downloads box.

Hope that helps.