The Navy doesn't use an "inverted star." You might be thinking of the inverted five-pointed star that's commonly seen on the U.S. Navy's uniform collar devices.

This inverted star, also known as a "gold star" or "service star" is used to denote combat service in the U.S. Navy.

Here's why it's inverted:

* Tradition: The tradition of wearing a gold star for combat service dates back to the Civil War, where it was originally worn on the breast.

* Visibility: When the star was moved to the collar, the inverted position made it more visible.

* Distinction: Inverted stars are generally worn to distinguish between different types of service awards. The upright star usually signifies a regular service award, while the inverted star often signifies combat service.

It's important to note that the meaning of the star can vary depending on the specific uniform and context. However, the inverted star is most commonly associated with combat service in the U.S. Navy.