29 CFR §4281.44

1. (a)Notice to PBGC. A notice of insolvency required under § 4281.43(a) to be filed with PBGC must contain the information and certification specified in the notice of insolvency instructions on PBGC's website (www.pbgc.gov).
2. (b)Notice to participants and beneficiaries. A notice of insolvency required under § 4281.43(a) to be issued to plan participants and beneficiaries must contain all of the following information—
   1. (1)The name of the plan.
   2. (2)A statement of the plan year for which the plan sponsor has determined that the plan is or is expected to be insolvent.
   3. (3)A statement that benefits above the amount that can be paid from available resources or the level guaranteed by PBGC, whichever is greater, will be suspended during the insolvency year, with a brief explanation of which benefits are guaranteed by PBGC under section 4022A of ERISA.
   4. (4)The name, address, and telephone number of the plan administrator or other person designated by the plan sponsor to answer inquiries concerning benefits.