(c)Addressing letters rogatory. To avert uncertainties and minimize possibilities for refusal of courts to comply with requests contained in letters rogatory in the form in which they are presented, it is advisable that counsel for the parties in whose behalf testimony is sought ascertain in advance if possible, with the assistance of correspondent counsel in the United States or that of a consular representative or agent of his nation in the United States, the exact title of the court, Federal or State as the case may be, which will be prepared to entertain the letter rogatory. In Federal practice the following form of address is acceptable:The U.S. District Court for the ______________________ (e.g. Northern, Southern) District of ____________________ (State) ____________________ (City) __________________, (State)
In instances where it is not feasible to ascertain the correct form of address at the time of preparation of the letter rogatory, and it will be left for counsel in the United States, or a consul or agent in the United States of the nation of origin of the letter rogatory to effect its transmission to an appropriate court, the following form may be used: "To the Appropriate Judicial Authority at (name of locality)."