Which term best describes a supplementary legal document that supports a case?

The term "brief" refers to a legal document that outlines the arguments and relevant facts of a case, and it is often submitted to a court to support a party's position. A brief typically summarizes the legal issues, refers to relevant statutes or case law, and offers a compelling argument for the desired outcome. This makes it a quintessential supplementary legal document that enhances the understanding of the case and aids the court in making an informed decision.

Other terms like "aliunde" and "ancillary" have specific uses in legal contexts but do not serve the same universal function as a brief. "Aliunde," derived from Latin, refers to evidence that comes from outside the original source, while "ancillary" typically describes supporting services or entities that are secondary to the primary activity. "Caveat emptor" translates to "let the buyer beware" and is a principle in contract law, emphasizing the buyer's responsibility to examine goods before purchase, rather than serving as a supportive document in a legal case.