Why the Royal Navy called them Town-class cruisers

Why were ships named for major British cities called the Town class rather than the City class?

Town was the Royal Navy's established umbrella category for place names, including cities, so the class label followed naval convention rather than current civic status.

The collective label was Town class because the ship names belonged to a naming tradition broad enough to include both towns and cities. A city can still be described generically as a town, while not every town holds city status. The same tradition ruled out proposals that would have violated established rules for naming capital ships after a monarch's spouse. Class labels carry institutional history and are not simply modern geographic descriptions.