4. High officials of the union
Except in so far as in any particular case any privilege or immunity is waived by the Union, any officer of the Union holding the office of Secretary General (including any officer acting for him or her during his or her absence from duty) shall be accorded in respect of himself or herself, his or her spouse and his or her children under the age of 21, the like immunity from suit and legal process, the like inviolability of residence and the like exemption or relief from taxes, other than income tax, as is accorded to an envoy of a foreign sovereign Power accredited to Her Majesty, his or her spouse and children, and exemption from income tax in respect of emoluments received by him or her as an officer of the Union.
D.