If for some reason you need to disable automatic conversion of underscores to hyphens, set the parameter `convert_underscores` of `Header` to `False`:

{* ../../docs_src/header_params/tutorial002_an_py310.py hl[10] *}

/// warning

Before setting `convert_underscores` to `False`, bear in mind that some HTTP proxies and servers disallow the usage of headers with underscores.

///

## Duplicate headers { #duplicate-headers }

            "msg": "Extra inputs are not permitted",
            "input": "plumbus",
        }
    ]
}
```

## Disable Convert Underscores { #disable-convert-underscores }

The same way as with regular header parameters, when you have underscore characters in the parameter names, they are **automatically converted to hyphens**.

import (
	"strconv"

	"github.com/minio/minio/internal/bucket/lifecycle"
)

//go:generate stringer -type lcEventSrc -trimprefix lcEventSrc_ $GOFILE
type lcEventSrc uint8

//nolint:staticcheck,revive // Underscores are used here to indicate where common prefix ends and the enumeration name begins
const (
	lcEventSrc_None lcEventSrc = iota
	lcEventSrc_Heal
	lcEventSrc_Scanner
	lcEventSrc_Decom
	lcEventSrc_Rebal

  static class EmptyTest {}

  static class EmptyTests {}

  static class EmptyTestSuite {}

  static class Foo {}

  @SuppressWarnings("IdentifierName") // We're testing that we ignore classes with underscores.
  static class Foo_Bar {}

  public static class PublicFoo {}

  static class FooTest {
    @SuppressWarnings("unused") // accessed reflectively
    public void testPublic() {}

    public Integer crudMode;

    /**
     * The name of the label type.
     */
    @Required
    @Size(max = 100)
    public String name;

    /**
     * The value of the label type (alphanumeric and underscore only).
     */
    @Required
    @Size(max = 100)
    @Pattern(regexp = "^[a-zA-Z0-9_]+$")
    public String value;

    /**
     * The paths to include for this label type.
     */

	}
}

// We want center dot (·) and division slash (∕) to work as identifier characters.
func isIdentRune(ch rune, i int) bool {
	if unicode.IsLetter(ch) {
		return true
	}
	switch ch {
	case '_': // Underscore; traditional.
		return true
	case '\u00B7': // Represents the period in runtime.exit. U+00B7 '·' middle dot
		return true
	case '\u2215': // Represents the slash in runtime/debug.setGCPercent. U+2215 '∕' division slash