31 Pa. Code § 23.63
If any solicitation on behalf of management or any other person has been made or if proxy material is ready for distribution prior to an opposition solicitation subject to this subchapter, a statement in duplicate containing the information specified in Schedule B, as described in Subchapter F (relating to required information for Schedules A and B), shall be filed with the Insurance Department by or on behalf of each participant in the prior solicitation, other than the insurer, as soon as reasonably practicable after the commencement of the opposing solicitation.
31 Pa. Code § 23.63
This section cited in 31 Pa. Code § 23.64 (relating to information as to additional participants); and 31 Pa. Code § 23.67 (relating to solicitations prior to written proxy statements).