Title: WP_Icon_Collections_Registry::is_registered
Published: August 20, 2026

---

# WP_Icon_Collections_Registry::is_registered( string|null $collection_slug ): bool

## In this article

 * [Parameters](https://developer.wordpress.org/reference/classes/wp_icon_collections_registry/is_registered/?output_format=md#parameters)
 * [Return](https://developer.wordpress.org/reference/classes/wp_icon_collections_registry/is_registered/?output_format=md#return)
 * [Source](https://developer.wordpress.org/reference/classes/wp_icon_collections_registry/is_registered/?output_format=md#source)
 * [Related](https://developer.wordpress.org/reference/classes/wp_icon_collections_registry/is_registered/?output_format=md#related)
 * [Changelog](https://developer.wordpress.org/reference/classes/wp_icon_collections_registry/is_registered/?output_format=md#changelog)

[ Back to top](https://developer.wordpress.org/reference/classes/wp_icon_collections_registry/is_registered/?output_format=md#wp--skip-link--target)

Checks if an icon collection is registered.

## 󠀁[Parameters](https://developer.wordpress.org/reference/classes/wp_icon_collections_registry/is_registered/?output_format=md#parameters)󠁿

 `$collection_slug`string|nullrequired

Icon collection slug.

## 󠀁[Return](https://developer.wordpress.org/reference/classes/wp_icon_collections_registry/is_registered/?output_format=md#return)󠁿

 bool True if the icon collection is registered, false otherwise.

## 󠀁[Source](https://developer.wordpress.org/reference/classes/wp_icon_collections_registry/is_registered/?output_format=md#source)󠁿

    ```php
    public function is_registered( $collection_slug ) {
    	return isset( $collection_slug, $this->registered_collections[ $collection_slug ] );
    }
    ```

[View all references](https://developer.wordpress.org/reference/files/wp-includes/class-wp-icon-collections-registry.php/)
[View on Trac](https://core.trac.wordpress.org/browser/tags/7.1/src/wp-includes/class-wp-icon-collections-registry.php#L207)
[View on GitHub](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/class-wp-icon-collections-registry.php#L207-L209)

## 󠀁[Related](https://developer.wordpress.org/reference/classes/wp_icon_collections_registry/is_registered/?output_format=md#related)󠁿

| Used by | Description | 
| [WP_Icon_Collections_Registry::register()](https://developer.wordpress.org/reference/classes/wp_icon_collections_registry/register/)`wp-includes/class-wp-icon-collections-registry.php` |

Registers an icon collection.

  | 
| [WP_Icon_Collections_Registry::unregister()](https://developer.wordpress.org/reference/classes/wp_icon_collections_registry/unregister/)`wp-includes/class-wp-icon-collections-registry.php` |

Unregisters an icon collection.

  | 
| [WP_Icon_Collections_Registry::get_registered()](https://developer.wordpress.org/reference/classes/wp_icon_collections_registry/get_registered/)`wp-includes/class-wp-icon-collections-registry.php` |

Retrieves an array containing the properties of a registered icon collection.

  |

## 󠀁[Changelog](https://developer.wordpress.org/reference/classes/wp_icon_collections_registry/is_registered/?output_format=md#changelog)󠁿

| Version | Description | 
| [7.1.0](https://developer.wordpress.org/reference/since/7.1.0/) | Introduced. |

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