Lets take a look.

Custom lists are useful when you want to sort a list into a sequence that is not alphabetical.

For example, here we have a list of four regions.

We can easily sort these regions alphabetically in ascending or descending order.

But what if we want to sort them from West to East?

Lets create a second list in that order.

To do that, navigate to the custom list area at File > Options > Advanced.

In the General, section, poke the Edit Custom Lists button.

Next, snag the list on the worksheet, and hit the Import button.

Youll see the new list appear to the left.

Click OK twice to return to the worksheet.

Now, when we used advanced sorting, we can use our custom list to sort.

Back in our pivot table, we need to see to it that custom lists are enabled.

Right-click anywhere in the pivot table, and select PivotTable Options.

Then opt for Totals and Filters tab, and confirm that the Use Custom Lists option is checked.