I heard from a gas guy that this is to ensure that only connectors made for gas usage are used and people don’t build crazy contraptions with plumber gear for flammable gases… Kinda makes sense.

Years ago I consulted for a French company and analyzed their processes. Heavily depended on Excel. They all pronounced Excel Sheet as “Excel Shit”. All day long it was sentences like"…and then I make an Excel Shit here", “… then I give the Shit to my colleague”. It was glorious… (and technically they were right).