Revised return rules: submission of a revised ST-3 fixes the relevant date for tax recovery to that submission. An assessee may submit a revised return in Form ST-3 in triplicate to correct mistakes or omissions within the prescribed revision period; a special shorter window applies for a transitional quarter. The date of submission of the revised return is the relevant date for recovery of service tax under the Act. Timely filers of the specified annual return may also submit a revised return within a short period after filing.