1We’re going to extend the green rope by adding the blue rope to it.
2Pass the green rope up through the bight of the blue rope and over one side of the blue rope.
3Go under the blue rope.
4Go over the blue rope and back under the green rope.
5Snug the knot.
This knot doesn’t appear in ABOK.
This is just a sheet bend (ABOK 1431) joining a doubled rope and one single rope.