A cadet is a military officer-in-training, or a trainee for law-enforcement or other uniformed officer jobs.
The Imperial Andermani Navy uses the term Kadett. The Royal Manticoran Marine Corps also uses the term Cadet, as do both the uniformed civilian Astro-control Service and the Merchant Marine. The civilian Diplomatic Corps and Special Intelligence Service uses the term Intern.
The heir of a peerage title (usually the eldest offspring of the title holder) is referred to as a cadet peer and is addressed as "my lord" (for males) or "my lady" (for females) and referred to in the third person as (for example) "Lord John Doe" or Lady Jane Doe."
In The Royal Manticoran Navy: The Official Honor Harrington Fan Association, Inc. (TRMN), the term cadet is most commonly used for Cadet Rangers of the Sphinx Forestry Commission, which is the rank given to members of the organization under the age of 18 years.
At 16 years of age, the Youth member has an option to either remain with the Sphinx Forestry Commission as a Senior Cadet Ranger, or transfer to another branch under the provisions of the Midship/Cadet/Kadett/Intern program. See AO 2307-09 for details.