Hypno-imprinting, which is alternatively known as sleep-imprinting, involved employing hypnosis as a means to firmly embed data into a person's memory. A typical example of this would be the transfer of strategic details to an individual on their way to a specific task.
Additionally, hypno-imprinting saw utilization in the brainwashing of Alliance prisoners held captive by the Galactic Empire. Subsequently, these prisoners were freed, and the hypno-imprinting compelled them to act as spies against the Alliance, all without the Rebels realizing their actions.