What is required when setting a validation rule for the 'DueDate' field to ensure it's greater than the 'Date' field?

When setting a validation rule for the 'DueDate' field to ensure it is greater than the 'Date' field, it is necessary to enclose the field names in square brackets. This is the accepted syntax in databases like Microsoft Access, whereby square brackets are used to identify field names, especially if they contain spaces or special characters. Using square brackets allows the database to accurately interpret the field names when applying the validation rule.

The other methods of notation would not function correctly. For example, using curly brackets or quotation marks is not the standard way to refer to fields in Access validation rules and would likely lead to errors or invalid expressions. Similarly, simply typing 'DueDate > Date' without brackets would not suffice, as the database would not recognize 'DueDate' and 'Date' as fields that require comparison. By utilizing the correct square bracket syntax, you ensure that the validation rule works as intended.