CSA 2.22:19/ANSI Z21.50:19

This Standard applies to newly produced vented decorative gas appliances (see Clause 3, Definitions), hereinafter referred to as appliances, constructed entirely of new, unused parts and materials and having input ratings up to and including 400,000 Btu/hr (117 228 W). These appliances are for:
a) use with natural gas;
b) use with propane;
c) direct vent gas appliances for manufactured home (USA only) or mobile home OEM installation or aftermarket installation convertible for use with natural gas and propane gas when provision is made for the simple conversion from one gas to the other (see Clauses 4.1.22 and 4.1.23);
d) direct vent gas appliances for manufactured home (USA only) or mobile home aftermarket installation for use with natural gas only or propane gas only (see Clause 4.1.23); and
e) direct vent gas appliances for manufactured home (USA only) or mobile home OEM installation for use with propane gas only (see Clause 4.1.22). The construction of vented decorative gas appliances for use with the above-mentioned gases is covered under Clause 4, Construction. The performance of vented decorative gas appliances for use with the above-mentioned gases is covered under Clause 5, Performance.