Section 10, The Income Tax (Deductions Citation

If any person intends to apply to the Board for leave toappeal under the proviso to sub-section (6) of section 65 of the Ordinance he shall support his application by affidavit showing the cause which prevented him from giving notice of appeal within the period prescribed by the sub-section aforesaid, and shall serve a notice of his application with a copy of such affidavit on the Commissioner.