How to make a data validation drop-down list arrow that is always visible in Excel.
This allows your users to visually see that there is an in-cell list without having to first click that cell.
The method used here does not require any Macros, VBA, Shapes, or Objects – it is 100% formatting combined with a simple formula that you can copy/paste from the downloadable file for this tutorial.
Drop-Down List in Excel (Microsoft)