Adding Prevent automation rule actions
The Prevent automation rule action prevents users from making a change and displays a message. You can add this action to before save triggers.
1. Select Prevent from the Action list in the Add Rule Action dialog box when you are configuring an automation rule.
2. Enter the Message to display when users attempt to make a change.
3. Click OK to add the action.
If a rule with a Prevent action passes, subsequent rules are not evaluated and the item is not saved.