_:n2c4f42b67f454187bff2e3b7f88bac5axb0
<http://schema.org/description>
"Excel contains a built-in preset for highlighting duplicate values with conditional formatting, but it only works at the cell level. If you want to find and highlight duplicate columns, you'll need to use your own formula, as explained below. To highlight duplicate columns, you can use a formula based on the SUMPRODUCT function. In the example shown, the formula used to highlight duplicate columns is: =SUMPRODUCT(($B$4:$E$4=B$4)*($B$5:$E$5=B$5)*($B$6:$E$6=B$6))>1"
<https://exceljet.net/formulas/highlight-duplicate-columns>