To be off the record means to say something in confidence without having it attributed to the speaker.
1. The film star promised to meet the journalist on the grounds that what they spoke would be off the record and not be published.
2. The Inspector convinced the informer to tell him the names of the gang members, saying that their conversation would be off the record and nobody would know about it.
3. The scientist agreed to tell the top officials about his patented design provided they kept the details off the record till he had made the final product.