Upon objection to public disclosure of any information sought to be elicited during a hearing, the presiding officer may in his or her discretion order that the witness shall disclose such information only in the presence of those designated and sworn to secrecy by the presiding officer. The transcript of testimony shall be held confidential. Copies of said transcript need be served only upon the parties to whose representatives the information has been disclosed and upon such other parties as the presiding officer may designate. This rule is subject to the proviso that any information given pursuant thereto, may be used by the presiding officer or the Commission if deemed necessary to a correct decision in the proceeding. [Rule 167.] [55 FR 28400, July 11, 1990]