I found a useful description of this situation at http://members.aol.com/bocon/vfpframe.htm


>I turned on RI, and it objects, "Cascade updates that are based on an expression-based index key may not behave as expected. The system has identified expression based keys in the following relationships."
>
> wellunit + wellinsp
>
>And indeed, I do have a Candidate index like that in my wellinspection file.
>
>Would SDT be useful by making a calculated field of this expression to fool RI?
>
>
>Thanks,
>Sylvia