Enter the following formula in, let's say P1, and copy down:

=IF(COUNTIF($K$1:$K$100,K1)>1,IF(N1=MAX(IF($K$1:$K$100=K1,$N$1:$N$100)),K
1,""),K1)

....confirmed with CONTROL+SHIFT+ENTER, not just ENTER. Adjust the
ranges accordingly.

Hope this helps!

In article <eEcAIQc$FHA.2324@TK2MSFTNGP11.phx.gbl>,
"Barbara Wiseman" <not@real.email.address> wrote:

> I have a list of codes in column K, and their dates in column N. Some of
> the codes are duplicated in column K. What I would like to do is in another
> column pick the code from column K, but only if it is unique, or if not only
> if it has the latest date in column N of all instances of that code.
>
>
>
> e.g.
>
>
>
> Col K Col N other column
>
> X123 1-Jan-2004
>
> X126 1-Feb-2004 X126
>
> X123 1-Dec-2005 X123
>
>
>
> The first example is blank as it is not unique and there is another instance
> with the same code, with a later date. The 3rd example is not unique, but
> does have the latest date of that code. The 2nd example is a unique code.
>
>
>
> I have got this far
>
> =IF(COUNTIF(K:K,K6)>1, ,K6)
>
>
>
> which is the easy bit, I know. So I test for uniqueness and if the code is
> unique I return the code. But how to fill in the blank to look at all the
> instances of the code if it is not unique, there may be up to 2, 3 or 4
> instances of some codes, and determine which has the latest date, and only
> put the code in the 'other column' if it is the latest dated of all the
> instances of that code?
>
>
>
> It may not be possible, but any suggestions would be welcome. I am quite
> happy to use a helper column if needed.
>
>
>
> Thanks,
>
> Barbara