What is the difference between off the record and not for attribution?

Answer 1

Off the record means that the information may be used to help you find other sources or probe more deeply. You can't quote it or say who said it.

Not for attribution means that you can't say who told you but can generally give some limited source information like, "A city official said today..."

For more detail check this link on sourcing in journalism:
http://www.answers.com/topic/journalism-sourcing