Lieutenant (navy)
"First lieutenant" in naval usage
The first lieutenant (1st Lt or 1LT) in the Royal Navy and other Commonwealth navies, is a post or appointment, rather than a rank. Historically, the lieutenants in a ship were ranked in accordance with seniority, with the most senior being termed the first lieutenant and acting as the second-in-command. Although lieutenants are no longer numbered by seniority, the post of "first lieutenant" remains.
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