Abatement for rail goods transport reduces taxable base where CENVAT credit has not been claimed, altering effective tax incidence. Abatement for services in relation to transport of goods by rail applies a reduced taxable base, producing an effective rate of tax determined as a portion of the service tax, conditional on non availment of CENVAT credit on inputs, capital goods and input services used for the taxable service; eligibility is tied to compliance with CENVAT Credit Rules and the scheme rests on statutory valuation and defined meanings of 'goods.'