Create any needed Profile Property Rules (also called Validation Rules) to define checks made against one or more fields when a record is modified. These Profile Property Rules can be assigned to one or more attributes.
Click on the Profile Property Rules tab.
Click the New option under the Action drop-down menu.
The Property Rule Editor window is shown.
Enter the Property Rule conditions.
Click the OK button to be returned to the Profile editor.
Click the Next button to move to the Define Attributes page.