(a) Representation. (1) The Internal Revenue Service may be represented in proceedings under this part by an attorney or other employee of the Internal Revenue Service. An attorney or an employee of the Internal Revenue Service representing the Internal Revenue Service in a proceeding under this part may sign the complaint or any document required to be filed in the proceeding on behalf of the Internal Revenue Service.

(2) A respondent may appear in person, be represented by a practitioner, or be represented by an attorney who has not filed a declaration with the Internal Revenue Service pursuant to § 10.3. A practitioner or an attorney representing a respondent or proposed respondent may sign the answer or any document required to be filed in the proceeding on behalf of the respondent.

(b) Ex parte communication. The Internal Revenue Service, the respondent, and any representatives of either party, may not attempt to initiate or participate in ex parte discussions concerning a proceeding or potential proceeding with the Administrative Law Judge (or any person who is likely to advise the Administrative Law Judge on a ruling or decision) in the proceeding before or during the pendency of the proceeding. Any memorandum, letter or other communication concerning the merits of the proceeding, addressed to the Administrative Law Judge, by or on behalf of any party shall be regarded as an argument in the proceeding and shall be served on the other party.

(c) Effective/applicability date. This section is applicable beginning August 2, 2011.