How archaic rank titles still work in modern navies

How do archaic rank terms continue to work in modern navies?

Navies adapt them through established usage, often using the ship-type qualifier to distinguish officers who share a captain title.

The French and Spanish systems keep sailing-era ship categories inside modern officer grades. In daily use, the qualifier such as frigate can distinguish one captain-grade officer from another. Established service practice tells the crew which officer actually holds command, so the historical wording does not create constant confusion. The answer demonstrates how a navy can preserve old institutional language while adapting it to modern ships and organizations.