When the qualifier for a security or validation rule is met, the operation attempted by the user is automatically rejected. You are only required to enter a message that appears for users when the operation is rejected. If the operation is approved, the rule does not display a message to the user.
Keep the following points in mind when writing messages for rules:
•The message may not only help the user understand what to do, but it may also help you identify which rule was triggered when users are having difficulties. For example, you may include a reference number that identifies the rule.
•If you do not specify a message, a generic message box is shown to users. Make sure to include a message that is descriptive and includes a possible solution for the user.
•Messages are limited to 2000 characters. If you type more characters than that, the extra characters will be truncated without warning.
Action Tab on Security or Validation Rule Screens
