Section 2700.21 - Effect of filing notice of contest of citation or order(a) The filing of a notice of contest of a citation or order issued under section 104 of the Act, 30 U.S.C. 814 , does not constitute a challenge to a proposed penalty assessment that may subsequently be issued by the Secretary under section 105(a) of the Act, 30 U.S.C. 815(a) , which is based on that citation or order. A challenge to such a proposed penalty assessment must be filed as a separate notice of contest of the proposed penalty assessment. See§ 2700.26 .(b) An operator's failure to file a notice of contest of a citation or order issued under section 104 of the Act, 30 U.S.C. 814 , shall not preclude the operator from challenging, in a penalty proceeding, the fact of violation or any special findings contained in a citation or order including the assertion in the citation or order that the violation was of a significant and substantial nature or was caused by the operator's unwarrantable failure to comply with the standard.58 FR 12164, Mar. 3, 1993, as amended at 71 FR 44207, Aug. 4, 2006