Let's say you are creating a form in ServiceNow and you want to set an input form field to disabled or read only. For example, let's say you have an input form field named on_call_group.

By default, input fields are not disabled or read only, meaning text can be entered into the input form field.

UI Policy can be used to set the input form field to disabled or read only. In this example, the UI Policy will set the on_call_group input form field to read only.

It is noteworthy that the on_call_group input form field must NOT be mandatory in order for the UI Policy to be able to set the input form field to read only.

And now indeed the input form field is read only, meaning text cannot be entered into the input form field. This is useful for input form fields that auto-populate.