b The central authorities shall communicate directly with each other; c Each Party shall, at the time of signature or when depositing its instrument of ratification, acceptance, approval or accession, communicate to the Secretary General of the Council of Europe the names and addresses of the authorities designated in pursuance of this paragraph; d The Secretary General of the Council of Europe shall set up and keep updated a register of central authorities designated by the Parties. Each Party shall ensure that the details held on the register are correct at all times. 3 Mutual assistance requests under this article shall be executed in accordance with the procedures specified by the requesting Party, except where incompatible with the law of the requested Party. 4 The requested Party may, in addition to the grounds for refusal established in Article 25, paragraph 4, refuse assistance if: a the request concerns an offence which the requested Party considers a political offence or an offence connected with a political offence, or b it considers that execution of the request is likely to prejudice its sovereignty, security, ordre public or other essential interests. 5 The requested Party may postpone action on a request if such action would prejudice criminal investigations or proceedings conducted by its authorities. 6 Before refusing or postponing assistance, the requested Party shall, where appropriate after having consulted with the requesting Party, consider whether the request may be granted partially or subject to such conditions as it deems necessary. 7 The requested Party shall promptly inform the requesting Party of the outcome of the execution of a request for assistance. Reasons shall be given for any refusal or postponement of the request. The requested Party shall also inform the requesting Party of any reasons that render impossible the execution of the request or are likely to delay it significantly. 8 The requesting Party may request that the requested Party keep confidential the fact of any request made under this chapter as well as its subject, except to the extent necessary for its execution. If the requested Party cannot comply with the request for confidentiality, it shall promptly inform the requesting Party, which shall then determine whether the request should nevertheless be executed. 51