Which of the following is not a typical term used in legal research?

A codicil is a legal term that refers specifically to a document that modifies or revokes a will. While it is a legal concept, it is not directly associated with the process of legal research, which typically focuses on finding statutes, case law, regulations, and other legal sources that establish legal principles or authority.

On the other hand, statutes are laws enacted by legislatures, precedents are prior judicial decisions that serve as a guideline for future cases, and subpoenas are orders to appear in court or produce evidence. These terms are fundamentally linked to the processes and materials involved in legal research, making them typical terminology within that context. Thus, codicil stands apart since it does not relate to the conduct of research in the law but rather to estate planning.