It's a bit naughty, because it isn't a name from any of those diagrams (and it needs a little explaining to non-UK dwellers). Many toilets in the UK for a number of decades were manufactured by a company called ARMITAGE SHANKS, and the name was proudly printed on each tank. They are a prog rock / psychedelic band, like Pink Floyd before Syd Barrett disappeared into his black hole. No on-stage orgasms, I'm afraid, but at the end of a particularly intricate noodling keyboard solo, the audience have started to make an appreciative noise like a toilet flushing.