I have tried various formulas to make this work and I'm spinning my wheels and hoping for help!
I would like in column D a Y or N to indicate the cells in that row are duplicates because they show up elsewhere in that column.
ROW Col A ColB ColC ColD
Dt Tmstamp Item ID Work Order Result
1 5/7/2015 14:20 142532 775502 N
2 5/7/2015 14:24 142416 775502 N
3 5/7/2015 14:25 142416 775502 Y
4 5/7/2015 14:25 142416 775502 Y
5 5/7/2015 14:25 142416 775502 Y
6 5/7/2015 14:48 171071 N

So rows 3, 4 and 5 are duplicates in my example would be the desired result of the formula which I'm trying to put into Column D. I have tried {=IF(ISNA(MATCH(1,($B145=sheet1!$B$1:$B$1000)*($D1 45=sheet1!$D$1:$D$1000)*($H145=sheet1!$H$1:$H$1000 ),0)),"n","Y")}, but all I get are Y's