One easy way is to use a helper column and count the number of times an entry
on a row appears in your list.
Lets say your list goes from A2 to A204 and column C is available as a
'helper' column. Put this formula in C2 and fill down to C204
=IF(COUNTIF(A$2:A$204,A2)>1,"DUPLICATE","")
It will display DUPLICATE on rows where there are, well, duplicate entries.
