The purpose of this section is to aid in the provision of housing accommodations for servicemen in the armed forces of the United States and their families, servicemen in the United States Coast Guard and their families, and servicemen in the United States National Oceanic and Atmospheric Administration and their families by supplementing the insurance of mortgages under section
1709 of this title with a system of mortgage insurance specially designed to assist the financing required for the construction or purchase of dwellings by those persons. As used in this section, a “serviceman” means a person to whom the Secretary of Defense (or any officer or employee designated by him), the Secretary of Homeland Security (or any officer or employee designated by him), or the Secretary of Commerce (or any officer or employee designated by him), as the case may be, has issued a certificate hereunder indicating that such person requires housing, is serving on active duty in the armed forces of the United States, in the United States Coast Guard, or in the United States National Oceanic and Atmospheric Administration and has served on active duty for more than two years, but a certificate shall not be issued hereunder to any person ordered to active duty for training purposes only. The Secretary of Defense, the Secretary of Homeland Security, and the Secretary of Commerce, respectively, are authorized to prescribe rules and regulations governing the issuance of such certificates and may withhold issuance of more than one such certificate to a serviceman whenever in his discretion issuance is not justified due to circumstances resulting from military assignment, or, in the case of the United States Coast Guard or the United States National Oceanic and Atmospheric Administration, other assignment.