You're wrong. (IANAL). Let's say I'm a freelancer, and I enter into an NDA with company X. As part of the NDA, there is a definition of what exactly is the inf

You're wrong. (IANAL). Let's say I'm a freelancer, and I enter into an NDA with company X. As part of the NDA, there is a definition of what exactly is the information that I need to keep confidential. Now, my lawyers will push for a definition which is very specific and very explicit. How? They'll want Company X to mark every piece of confidential information with some kind of "confidential" mark. This way, I know explicitly about every piece of information that is supposed to be confidential. Now, I'm guessing this is the same basic logic that big companies use when having this disclaimer. Anyone they've signed any kind of confidentiality agreement with might need to be explicitly told that this information is confidential.