Based on customer requests for more robust compliance features, Microsoft has improved the validation capabilities of lists and libraries. Validation is now supported at both list and item levels.

For instance, a list owner can configure a validation to disallow the start date of an event item (stored in one column) to be after the end date of the event (stored in another column). If a user enters a start date that is later than the specified end date they will be presented with an error message when he or she attempts to save the item.

In another example, people can specify a column in a list as unique so that a contact list may not contain two entries with the same email address.