Condition format highlight duplicates between sheets

[Newbienew]

Good day Experts,

I watch a lot of youtube videos, countif, vlookup, if formulas but it would seem that all that I tried is just not working for me. I have a sheet with specific Alphanumeric data and another with sheet I have a longer list of various alphanumeric data. I would only like to highlight the specific alphanumeric data on the second sheet. May I please ask for your assistance thank you .

 

[6StringJazzer]

It helps to make your description concrete with regard to sheet names and cell references. I am going to guess, and give you a solution that will highlight any items in column A of Sheet2 that appear in column A of sheet 1.

Applies to:
Sheet2!$A:$A

Rule using a formula:

=COUNTIF(Sheet1!$A:$A,A1)>0

 

[Newbienew]

Sorry my specific sheet doesnt have a name yet. So it would be sheet1. The sheet with all the alphanumeric numbers is Main Data Sheet.

 

[6StringJazzer]

You can update my answer to suit your specifics.