Gag law, (command); a command given while a Master is having a slave, forbidding her speech, restricting her to moans and whimpers. [see also: gagged by master´s will; modality of the mute slave]

When she had been used before my kennel, she had been under 'gag law', as is common when the guards use a girl, forbidden speech, save for moans and whispers.
Book 22, Dancer: Page 65