After Truecaller CEO Rishit Jhunjhunwala criticised TRAI's restrictions on spam tagging of 140- and 1600-series numbers, it clarified that 1600-series numbers are reserved for trusted calls by regulated BFSI entities and the government. It added that users of the 140-series have to register with telecom operators. Tagging, blocking or filtering of 1600-series numbers isn't allowed, TRAI said.