Statutory film certification exempt from service tax as a sovereign function; CBFC certificates not treated as taxable services. Certification of films under the Cinematographic Act, 1952 is a mandatory statutory requirement to determine suitability for public exhibition. The Board has clarified that activities assigned to and performed by a public authority under law constitute a sovereign function and do not amount to a taxable service; accordingly, certification performed under the Act does not constitute a service subject to service tax and fees collected are not treated as consideration for levy.