ART 164: Where the rogatory letters or instrument of judicial delegation prescribes simultaneous operations in various parts of the territory, reproductions or full copies of the original, by order of the investigating judge, may be sent to the investigating judges and judicial police officials responsible for its execution. In urgent cases, rogatory letters or instrument of judicial delegation may even be disseminated by any means. Each copy must, however, specify the essential terms of the original and, in particular, the nature of the charge, the name and the position of the issuing magistrate. Section VII - Expert Opinions ART 165: Any investigating or trial court may order an expert opin ion where a technical issue arises, either at the request of the Public Prosecutor, upon the application of the parties, or of its own motion Where the investigating judge considers that he/she need not grant a request for an expert opinion, he/she must pass a reasoned order to this effect Experts shall carry out their task under the supervision of the investigating judge or the magistrate designated by the court ordering the expert opinion. ART 166: Experts shall be chosen from a list established by the Court of Appeal Conditions for registration and removal from this list shall be fixed by decree. In exceptional cases, the courts may, by means of a reasoned decision, choose experts not registered on this list. The task of experts, which may concern only the examination of technical issues, shall be specified in the decision ordering the expert opinion. ART 167. Where the decision ordering the expert opinion is issued by the investigating judge, it must be notified to the Public Prosecutor and the parties as well as specifies the names and positions of the expert or experts, as well as the wording of the task given. This decision shall not subject to appeal. However, within three days of its notification, the Public Prosecutor and the parties may make their submissions in a non-contentious manner. These submissions may concern either the choice or the task of the expert or designated experts. ART 168: At the time of their registration, the experts shall take, before the court of their domicile, an oath "to carry out their mission, to prepare their report and to give their opinion upon their honour and conscience". These experts shall not have to renew their oath whenever they are appointed. Experts not on the list, whenever they are appointed, sha ll take the oath provided for in the preceding paragraph before the investigating judge or the magistrate designated by the court. The official record of the oath taking ceremony shall be signed by the competent magistrate, the expert and the court registrar. In the case of an impediment, the grounds of which must be stated, the oath may be sworn in writing and the letter of the oath shall be attached to the case file. ART 169: Any decision designating experts must set a time limit within which they should complete their task. If special reasons so require, this time limit may be extended at the experts’ request and through a reasoned decision made by the judge or the court which designated them. Experts who do not file their report within the time limit set for them may be replaced immediately and must report the investigations they have already made. 32