Article 32 1. The immunity from jurisdiction of diplomatic agents and of persons enjoying immunity under article 37 may be waived by the sending State. 2. Waiver must always be express. 3. The initiation of proceedings by a diplomatic agent or by a person enjoying immunity from jurisdiction under article 37 shall preclude him from invoking immunity from jurisdiction in respect of any counterclaim directly connected with the principal claim. 4. Waiver of immunity from jurisdiction in respect of civil or administrative proceedings shall not be held to imply waiver of immunity in respect of the execution of the judgement, for which a separate waiver shall be necessary. Article 33 1. Subject to the provisions of paragraph 3 of this article, a diplomatic agent shall with respect to services rendered for the sending State be exempt from social security provisions which may be in force in the receiving State. 2. The exemption provided for in paragraph 1 of this article shall also apply to private servants who are in the sole employ of a diplomatic agent, on condition: (a) That they are not nationals of or permanently resident in the receiving State; and (b) That they are covered by the social security provisions which may be in force in the sending State or a third State. 3. A diplomatic agent who employs persons to whom the exemption provided for in paragraph 2 of this article does not apply shall observe the obligations which the social security provisions of the receiving State impose upon employers. 4. The exemption provided for in paragraphs 1 and 2 of this article shall not preclude voluntary participation in the social security system of the receiving State provided that such participation is permitted by that State. 5. The provisions of this article shall not affect bilateral or multilateral agreements concerning social security concluded previously and shall not prevent the conclusion of such agreements in the future. Article 34 A diplomatic agent shall be exempt from all dues and taxes, personal or real, national, regional or municipal, except: 10