How to prevent duplicate entries in a SharePoint list or library by using Enforce Unique Values

can you enforce no DUP records in a sharepoint list using 2 fields together? For example, i can have multiple entries for the same person, but the combo of person and date must be unique.

For an attendance list I want to use data validation in SharePoint that employee name/number should be used once on the particular date. Daily basis there shouldn't be any duplicate entry how to do it?

Hi Greg,
I have found your SharePoint videos very educational and request you to please help me with a query....

I have let's say three terms in my termset say A,B,C and many documents are tagged to it now my requirement is to replace all the three terms with D such that all the documents tagged to A,B,C are now tagged to D and A,B,C are removed.

Thanks Greg! Excellent work, as always, extremely informative and helpful. Big ups from Australia