Last time this came up, I learned that the piece we in the west call queen (you guys in English anyway, in German its Dame (meaning Lady)) is actually called Vesir/Consultant in that region. I think Wikipedia has a list per language, quite interesting.

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.