Excel Unique List Formula

In one column I have repeating state codes—WA, WA, SA, SA, ACT, ACT, WA, WA—and I simply need an automatic way to display each code once. The duplicates should disappear (no highlighting, no counting) and the tidy, de-duplicated list must appear in a new column right beside the source data.

A neighbouring column already holds the running total of uniques (currently 3 for WA, SA, ACT), so your solution only has to focus on extracting the distinct values themselves.

Please provide a single formula (or a compact, copy-ready combination of formulas) that I can drop into the worksheet without restructuring anything else. It should work regardless of future changes in the original column’s length. If different Excel versions require slightly different syntax, include each variant clearly so I can choose the one that matches my installation.