Answer:
The requirement is that the notice be sent to all homeowners who are in default on a residential mortgage. You can learn more in HUD Mortgagee Letter 2006-28 issued 11/20/2006. There is a link to information about the form, a corrected version of the form, and a link to the referenced mortgagee letter here: http://www.bankersonline.com/tools/lender/hud_scra.html