Also known as the Ashley stopper knot! I've started keeping a short length of paracord on my desk to practice knots during video calls. It makes a great fidget toy. The Ashley stopper is what I've been tying this week and it's such a gem (but a little harder to untie than I'd like).
ABOK is the classic. But I was surprised to learn recently that it's not the final word on knots. Superior knots like the Zeppelin bend don't appear in it and there have even been useful knots invented since it was published. Geoffrey Budworth's "The Ultimate Encyclopedia of Knots and Ropework" includes knots that were invented in the 80s.