Properties which are set as Read-only are properties that values cannot be changed by the user. The read-only properties are used to get their values dynamically based on a specific rule.
Read-only type of Properties cannot be required. When a Property have been set as Read-Only, the Value is required option could not be selected in the Basic Information page of the Property Wizard.
The read-only properties can be retrieved from the external data source but they cannot have any functions.