Final answer:
A rule that establishes who may testify on your behalf in court is a procedural rule of law, not a substantive rule of law.
Step-by-step explanation:
A rule that establishes who may testify on your behalf in court is an example of a procedural rule of law, not a substantive rule of law. This is because it governs the proper conduct and process of the legal system, rather than defining rights and responsibilities.
Substantive rules of law, on the other hand, establish the rights and duties of individuals and entities. They address the legal consequences of certain actions or events. For example, a substantive rule of law could determine whether a person is liable for damages in a civil lawsuit, or whether a person can be found guilty of a crime in a criminal trial.
In summary, a rule that determines who can testify in court is a procedural rule of law, not a substantive rule of law.