Income-tax rules: mandatory electronic filing, digital verification, and new Form 26B for Chapter XVII-B refund claims. The amendments mandate electronic furnishing and verification (by digital signature or electronic process) for specified TDS/TCS statements and accountant certificates, require that the systems authority prescribe procedures, formats and standards and administer day-to-day operations, and insert Form 26B as the electronic form for deductors to claim refunds of sums paid under Chapter XVII-B; several statutory forms and rules are substituted to align quarterly statements, declarations and certificates with this electronic regime.