Just in case we want to try to figure out the obscure mystery shopping company that is doing some of them, I won't come out and say it. It is a convenience store brand and not an oil company. There are actually a small percentage of locations California that don't even sell gas. Sometimes the gas is convenience store store branded, and sometimes the convenience store partners with a nationwide oil company . There have been times where I have done the convenience store mystery shop and the gas brand mystery shop at the same location.
It's a shape and then a letter all combined into one symbol. The name of the convenience store is "round shape" "constant letter"