§ 3007 Testimony or written admission of party.

If you want to prove what's in a document, there's an easier option when the other side already knows what it says. You can use their own testimony, their deposition, or something they wrote admitting to its contents. This works instead of bringing in the original document itself.

Normally, if you want to prove what a record says, you need to explain why you don't have the original copy. But this rule skips that requirement in one specific situation. If the person you're up against in the case has already testified about the document, given a deposition about it, or put something in writing admitting what it contains, you can just use that instead. You don't have to track down the original or explain why it's missing.

This makes sense because the other party already confirmed what the document says. There's no real dispute to resolve by hunting down the original paper. Their own words serve as reliable proof of the content.