Article 6
Enforcement requested in accordance with the foregoing provisions may not be refused, in whole or in part, save:
(a) where enforcement would run counter to the fundamental principles of the legal system of the requested State;
(b) where the requested State considers the offence for which the sentence was passed to be of a political nature or a purely military one;
(c) where the requested State considers that there are substantial grounds for believing that the sentence was brought about or aggravated by considerations of race, religion, nationality or political opinion;
(d) where enforcement would be contrary to the international undertakings of the requested State;
(e) where the act is already the subject of proceedings in the requested State or where the requested State decides to institute proceedings in respect of the act;
(f) where the competent authorities in the requested State have decided not to take proceedings or to drop proceedings already begun, in respect of the same act;
(g) where the act was committed outside the territory of the requesting State;
(h) where the requested State is unable to enforce the sanction;
(i) where the request is grounded on Article 5 (e) and none of the other conditions mentioned in that Article is fulfilled;
(j) where the requested State considers that the requesting State is itself able to enforce the sanction;
(k) where the age of the person sentenced at the time of the offence was such that he could not have been prosecuted in the requested State;
(l) where under the law of the requested State the sanction imposed can no longer be enforced because of the lapse of time;
(m) where and to the extent that the sentence imposes a disqualification.