My question is similar to this one, but adds a little more complexity.
How can I flag duplicate entries in a Google Sheets column unless the duplicates have different values in another column? For instance, consider the table
col A col B
--------------
abc 123
def 123
ghi 456
ghi 456
How can I flag the last two rows which are the same in both col A
and col B
but not the first two which differ in col A
?