26 CFR § 55.6694-2
Penalties for understatement due to an unreasonable position
June 25, 2020
(a) In general. A person who is a tax return preparer of any return or claim for refund of excise tax under chapter 44 of subtitle D of the Internal Revenue Code (Code) shall be subject to penalties under section 6694(a) of the Code in the manner stated in §1.6694-2 of this chapter.
(b) Effective/applicability date. This section is applicable to returns and claims for refund filed, and advice provided, after December 31, 2008.
[T.D. 9436, 73 FR 78459, Dec. 22, 2008]