Kolkata, Oct 11 - Anti-tax avoidance measures like GAAR should be used sparingly and not to raise revenue for the government, said Parthasarathi Shome who heads the government committees on taxation matters.  "We saw GAAR as a very very special instrument for controlling tax avoidance ... We have to protect our revenue but with these kind of anti-avoidance methods we cannot be expanding our revenues," Shome said at Merchant Chamber of Commerce & Industry event here.