This standard applies to decorative gas appliances for installation in solid-fuel burning fireplaces, which are constructed entirely of new, unused parts and materials: a. for use with natural gas; b. for use with propane; c. for use with natural and convertible for use with propane gas; d. for manufactured home (US only) or mobile home installation for use with natural and convertible for use with propane gas; and e. for manufactured home (US only) or mobile home installation for use with propane gas only.