Service tax return scrutiny limited to detected anomalies; taxpayers contacted only for short-levy or filing errors by superintendent. Instructions require that service tax return scrutiny be conducted using return data without informing taxpayers; contact with taxpayers is permitted only when checks reveal short-levy, non-levy, arithmetical inaccuracies or errors in filling the return form. Any contact must be undertaken by an officer not below the rank of Superintendent of Central Excise, with a record of communication maintained and subject to periodic senior review.