effective exchange of information, mutual agreement procedures and co-operation between and amongst themselves. 4. Member States will, in pursuit of a common policy for dealing with tax treaties, develop a model tax treaty for SADC that, amongst other things, takes account of the particular socio-economic development needs of Member States. 5. Member States will, on completion of the envisaged model tax treaty for SADC, draw up guidelines for the effective exchange of information and the implementation of mutual assistance and co-operation procedures. ARTICLE 6 INDIRECT TAXES 1. Member States accept that it is in the interest of the Community that there be effective co-ordination and harmonisation in the administration of indirect taxes. 2. Member States will, in line with the World Trade Organisation (WTO) Agreements, gradually substitute taxes on internationally traded goods and services with broadbased taxes on consumption. 3. Member States will explore areas of possible co-ordination for policy formulation and administration in respect of excise duties on: (a) tobacco products; (b) alcoholic beverages; (c) non-alcoholic beverages; (d) fuel products; (e) luxury goods; and (f) any other excisable goods. 4. Member States will, as far as is possible, promote the use of excise duty on an ad valorem basis on luxury goods and services as an alternative to the application of multiple VAT or sales tax rates, provided that it is accepted that the classification of goods and services as being "luxury" may, due to shifts in economic and social conditions, change from time to time. 5. Member States will, in an effort to minimise incidents of smuggling, take such steps as are necessary to harmonise the application of excise duty rates, with specific regard to tobacco products, alcoholic beverages and fuel products. 8