Explain to your audience what it means when a source is ‘off the record’

From middlewick on Morguefile

Reporter wants to report all of his or her information on the record, but sometimes, despite your best efforts, you need to use a source that is off the record. There are cases where this can be done, but does your audience understand how that works?

The New York Times this week published an explanation of what it means when they report that something is “off the record.”

What could broadcasters do to explain the use of off the record sources to their audiences?