The omoplata (referred to in judo as ashi-sankaku-garami, 三角緘, "triangular entanglement"and in catch wrestling as coil lock) is also a commonly featured shoulder lock in Brazilian Jiu-Jitsu. The locking mechanism is similar to the kimura lock, but instead of using a figure-four, it is applied using a leg.
The omoplata can be applied from the guard, by placing one leg under the opponent's armpit and turning 180 degrees in the direction of that leg, so that the leg moves over the back of the opponent and entangles the opponent's arm.
By controlling the opponent's body and pushing the arm perpendicularly away from the opponent's back, pressure can be put on the opponent's shoulder. It is also possible to put pressure on the elbow joint by bending the leg entangling the arm, and twisting it in a specific manner. In order to secure the opponent and prevent him from rolling out of the lock, the inner arm can be thrown over the opponent's waist as a "seatbelt" securing the opponent.
Though an effective lock, it is more difficult than other armlocks to successfully apply, thus rarely seen in UFC fights.
To successfully complete this task, you must demonstrate the technique exactly as Sensei Nardu describes with your training partner in a controlled, safe environment. For bonus points, include video of yourself executing the technique during sparring / live rolling (note, this is optional and not required for you to pass this task).