Audit report form requirement for deduction claims under section 80HH was prescribed in Form No. 10C. Rule 18B dealt with the form of audit report for claiming deduction under section 80HH. It applied to an assessee other than a company or a co-operative society and required the report furnished under sub-section (5) of section 80HH to be in Form No. 10C. The rule was later omitted by notification dated 29 July 2021.