Executive Rule No. 30 establishes the regulations for the depreciation of fixed assets for an Incorporated Body's tax declaration. It mandates the straight-line method and specifies maximum annual depreciation rates for various asset categories, such as buildings, vehicles, and computers. The rule stipulates that assets must be owned by the body and necessary for business in Kuwait. It disallows goodwill amortisation and outlines procedures for requesting alternative depreciation methods or handling changes in policy, which require Tax Department approval and only apply to new assets.