yogi_Conditionally Format Cell B2 To B If The Entry In Column B Also Occurs In B2 To B In Sheet1

                           Google Spreadsheet   Post  #1715
Yogi Anand, D.Eng, P.E.      ANAND Enterprises LLC -- Rochester Hills MI     www.energyefficientbuild.com.   Jul-30-2014
post by scooter69:
(https://productforums.google.com/forum/#!mydiscussions/docs/LuDUM11pipo)
Using Countif across multiple sheets

Is it possible to use countif across multiple sheets to weed out duplicates?

I have a database of names and twitter handles spread onto 3 sheets and for the sake of this post I cannot merge them all into 1 sheet and I don't want to use any scripts / add-on's (the add-on I was using works fine, but it doesn't update itself. I have to re-run it every time I make a new entry to check if I am duplicating something that is on one of the other 3 pages)

I currently have countif forumulas that highlight duplicates within single columns on individual sheets. So on 'Sheet 1' in Column A I can see duplicates that are in 'Sheet 1' Column A, but I cannot see if there are any duplicates between 'Sheet 1' Column A and 'Sheet 2' Column A.

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I did not use the COUNTIF() function ... in the following is a solution
using MATCH() function