In a foreign country, depositions may be taken (1) on notice before a person authorized to administer oaths in the place in which the examination is held, either by the law thereof or by the law of the United States, or (2) before a person commissioned by the court, and a person so commissioned shall have the power by virtue of the commission to administer any necessary oath and take testimony, or (3) pursuant to a letter rogatory. A commission or a letter rogatory shall be issued on application and notice and on terms that are just and appropriate. It is not requisite to the issuance of a commission or a letter rogatory that the taking of the deposition in any other manner is impracticable or inconvenient; and both a commission and a letter rogatory may be issued in proper cases. A notice or commission may designate the person before whom the deposition is to be taken either by name or descriptive title. A letter rogatory may be addressed “To the Appropriate Authority in (here name the country).”Evidence obtained in response to a letter rogatory need not be excluded merely for the reason that it is not a verbatim transcript or that the testimony was not taken under oath or for any similar departure from the requirements for depositions taken within the United States under these rules.