This position is the most commonly used. There are many variations of it (also see Tower Nadu) but this is most standard. The slave drops to her knees before the Master (Tower Nadu before a Mistress), her thighs part widely and she rests her butt onto un-crossed ankles. Her back straight or slightly arched she lifts her chin proudly and drops her eyes submissively. Her hands should be resting palm upwards and open against her thighs to indicate complete vulnerability, surrender, and submission to the Will of the Master, or placed palms down to indicate that the slave is not available for sexual usage. Note that this is also known as the Position of the Gorean Pleasure Slave, assuming this position tells the Master or Mistress that you are ready to serve them, sexually.

Commanding a slave to sit nadu with crossed ankles is considered a punishment because of the pain this variation causes within ten minutes.

Book 17, page 155
"Come now, my pretty slaves,' said Ginger, "kneel straight. Back straight, heads up. Back on your heels there! Spread those pretty knees. Yes, that is the way men like it. Put your hands, palms down, on your thighs. Good. good. Excellent!" The girls now knelt in the coffle as pleasure slaves.

Book13, page 77
"Nadu!" he snapped. She swiftly turned, facing him, and dropped to her knees. She knelt back on her heels, her back straight, her hands on her thighs, her head up, her knees wide. It was the position of the pleasure slave."