Hmm. That says to me that the Brits would/could call ANY open-end wrench a "spanner." Looks like yer standard DOE to me. I'd learned when young that a "spanner" has an open arc (on one end of a straight handle) with a "hook" at one end of the arc to snag one of the ears on, say, a fire hose fitting. No "tight/smooth fit" required, like is needed on battery cable nuts.