Senatus consultum (Nova Roma)
A senatus consultum is an official statement and advice of the Senate to the executive magistrates. Though it is officially an "advice" from the Senate to a magistrate, and technically these decrees do not have to be obeyed, in practice, they usually are. If a senatus consultum conflicts with a law that has been passed by the comitia, the law overrides the senatus consultum, because the senatus consultum has its authority based in precedent, and not in law. A senatus consultum, however, can serve to interpret a law.
See the list of senatus consulta: