6d. Upon receipt of the petition initiating the appeal, the secretary of the Board shall note the date and time of receipt on the petition and docket the appeal in a docket kept for that purpose. Where the petition is received by mail the envelope containing the postmark shall be retained. The case shall be assigned a number. An original and eight copies of the petition shall be filed, one copy of which shall be promptly served by hand delivery by the secretary of the Board upon the Director of Revenue, or his designee.
6e. Within 20 days after service upon; him of a copy of the petition, the Director of Revenue shall file an answer to the petition. The answer shall be so drawn as fully and completely to advise the petitioner and the Board of the defense. It shall contain specific admission or denial of each material allegation of fact contained in the petition and a statement of any additional facts upon which the Director of Revenue relies for defense or for affirmative relief or to sustain any issue raised in the petition in respect to which issue the burden of proof is or may be by statute ; placed upon the Director of Revenue. Paragraphs of the answer shall be numbered to correspond to those the petition to which they relate. An original and five copies of the Director of Revenue’s answer shall be filed with the Board and the Director of Revenue shall serve one copy thereof on the petitioner or his counsel of record, in person or by mail.
6f. No reply to an answer is required, but the petitioner may serve and file a reply to the answer within 10 days after service on him of such answer.
6g. A proceeding shall be deemed to be at issue upon the filing of the reply, or, if no reply be filed, upon the expiration of the time within which a reply may be filed.
6h. All motions to amend, made prior to the hearing must be accompanied by the proposed amendments or amended pleadings.
Upon motion made, the Board may, in its discretion at any time before the conclusion of the hearing, permit a party to a proceeding to amend the pleadings in stated petitions to conform to the proof.