This is a great article from Macworld on iTunes and understanding the sorting tags.
Even though it is based on the Mac it applies to Windows users as well
“iTunes lets you apply and edit information about your content; this metadata is called “tags.” Tags include the name of an item, its creator (or artist), an album name, a track number, and more.
But there are some iTunes tags that can be a bit confusing: the Sorting tags.
Here’s a look at what these tags are for and how you can use them to your advantage.”