The term "full disclosure" refers to a need in any business transaction that requires a party to tell the complete truth. This truth can be about any matter, which another party might require before deciding to contract or buy.
In real estate transactions (sale), many states requires a full disclosure form to be filled out and signed, which puts the party (the seller) under the penalty for knowingly concealing or falsifying an important fact about the property being sold.
Many courts require parties to sign a prenuptial agreement, which makes a full disclosure of all the assets of both the parties.