①An interested person (meaning a person other than the appellant who is found to have an interest in the disposition to which the appeal pertains in light of the laws and regulations on which that disposition is based; the same applies in the following paragraph) may participate in the appeal with the permission of the President of the National Tax Tribunal, etc.

②The President of the National Tax Tribunal, etc. may, if they find it necessary, request an interested person to participate in the appeal.

③The provisions of Article 107 (Agents) apply mutatis mutandis to participation in an appeal by an intervenor (meaning a person who participates in the appeal pursuant to the provisions of the preceding two paragraphs).