What are common GAS valve markings?

Warning:

WOG does NOT cover combustible gases. Valves for natural gas and liquid propane, for example, must have the required gas approvals from CSA.  Always make sure to verify and follow the installation codes for your area! WOG ratings do not cover flammable gases, natural gas or liquid propane.

Valves for GAS service, liquid propane (LP) or natural gas (NG), must be certified and bear the CSA mark along with the applicable marking for the type of gas application.