You can create a drop-down list of valid entries that is compiled from cells on a worksheet to make data entry easier, or to limit entries to certain items that you define.
To create a list of values for the drop down list, you can enter the list in consecutive rows anywhere in the worksheet, or in a separate worksheet in the same workbook.


In the cell(s) where you have assigned the validation, a small drop-down prompt will appear. When selected, it will display all of the items from the list in alphabetical order. You can choose a value from that list. If you choose to enter a value manually, it must be in the list. If you enter an incorrect value, the following message will appear.
Vince Verbeke, IT Specialist