Assuming your identifiers are numeric and each row of the group has the same
identifier

Select the rows you wish to format

Format/Conditional Formatting

Formula is: =MOD($A1,2)=0
then set your format

Replace $A1 with your first row of data and note that the placement of the $
sign is important.

HTH

PC


"Brandie" wrote in message
...
I have a spreadsheet with about 4000 lines of data. The lines are grouped
by
an unique identifier. One unique identifier has several lines that go with
it. I wanted to use a conditional format to highlight every other group of
data. For example:

1
1
2
2
3
3

Is there a way to highlight both of the 1's and skip the 2's and then
highlight the 3's or is this just a task to do by hand?