Answer:
There is model language in the new Appendix B to section 208.25 of FRB Regulation H, available here: https://www.bankersonline.com/regulations/12-208-025
You'll find the new Appendix B at the very bottom of that page.
You should use the model language, followed by instructions to the borrower on how to proceed to take advantage of the escrow option.
Each prudential regulator has made similar changes to its regulations on Loans in Areas Having Special Flood Hazards.