S.C. Code Ann. § 42-1-705

(A) The commission's Employer's Answer to Request for Hearing form, hereinafter referred to as Form 51, must describe with as much specificity as possible the defenses to be relied upon by the defendants. A Form 51 shall not state that "all defenses apply" or other similar language, unless such is actually the case. A Form 51 which does not conform to the requirements of this subsection shall not be considered at a hearing. (B) Nothing in this section prohibits a commissioner from considering a defense not listed on a Form 51 if: (1) it is proven to the satisfaction of the commissioner that the defendants had no knowledge of the facts supporting the defense on the date of the completion of the Form 51; and (2) in the case of represented defendants, the defense omitted on the Form 51 is set forth on the commission's Prehearing Brief form, and such brief is timely filed with the commission and timely served upon the parties. (C) A Form 51 must be signed by an attorney, verifying that the contents of the form are accurate and true to the best of the attorney's knowledge. If the employer is unrepresented and completes a Form 51, the employer must sign the form, verifying that the contents are accurate and true to the best of the employer's knowledge.