Cross-validation (also known as cross-segment validation) controls the combinations of values you can create when you enter values for key flexfields. A cross-validation rule defines whether a value of a particular segment can be combined with specific values of other segments. Cross-validation is different from segment validation, which controls the values you can enter for a particular segment.
You use cross-validation rules to prevent the creation of combinations that should never exist (combinations with values that should not coexist in the same combination). For example, if your organization manufactures both computer equipment and vehicles such as trucks, you might want to prevent the creation of "hybrid" part numbers for objects such as "truck keyboards" or "CPU headlights".
More>>http://download.oracle.com/docs/cd/A60725_05/html/comnls/us/fnd/crossval.htm#e_cvrl
