Custom validation with formula
=COUNTIF($A$1:$A$10,A1)+COUNTIF($A$15:$A$20,A1)<2

Jerry

andrewm wrote:

> Hi - I have a roster in which in a range a1:a10, a15:a20 I will be
> putting names in.
> eg. andrew, charles, abdul, tony. Andrew or Charles, and abdul or
> tony can only occur once. how can I do a data validation on this.
>
> ie. andrew or charles can occur only once, abdul or tony can occur
> only once in the ranges
>
> A1:A10, A15:A20
>
> thanks
>
> andrewm