# Upper Case Normalizer

The `upper` normalizer maps all Unicode letters in the given value to their upper case. It can be mixed with checkers and other normalizers when defining the validation steps for user data.

```golang
type User struct {
  Username string `checkers:"upper"`
}

user := &User{
  Username: "chECker",
}

fmt.Println(user.Username) // CHECKER
```