Setup

• Retail POS for Mac or PC
• OpenOffice, Excel or Google Sheets

Steps

1. Navigate to Catalog -> Products
2. Click Export List...
3. Open product CSV
4. Insert a new column to the right of the "sku" column
5. In the new column, paste the following formula:
   For Open Office: =IF(COUNTIF(C$2:C$500;C2)>1;"Duplicate";"Unique")
   For Excel/Google Sheets: =IF(COUNTIF(C2:C500,C2)>1,"Duplicate","Unique")
6. Click on the cell and drag down

Additional information

If you are going to look in a bigger spectrum of rows, modify the formula accordingly

I.e.: For 1000 rows, use:

For Open Office: =IF(COUNTIF(C$2:C$1000;C2)>1;"Duplicate";"Unique")
For Excel/Google Sheets: =IF(COUNTIF(C2:C1000,C2)>1,"Duplicate","Unique")