++++ 1.Tax provisions - Harmonization of laws - Turnover taxes - Common system of value-added tax - Sixth Directive - Territorial scope - Transport services carried out between two points within national territory but partly outside it - Requirement to tax - None - Consequence - Exclusion from the own resources basis ( Council Regulation No 2892/77; Council Directive 77/388 ) 2.Community law - Principles - Legal certainty - Rules capable of entailing financial consequences - Common system of value-added tax as a basis for the system of own resources of the European Communities