diff --git a/lib/experimental/fonts/font-library/class-wp-font-collection.php b/lib/experimental/fonts/font-library/class-wp-font-collection.php
index 79b0691ede2733..6189da5fa984b1 100644
--- a/lib/experimental/fonts/font-library/class-wp-font-collection.php
+++ b/lib/experimental/fonts/font-library/class-wp-font-collection.php
@@ -43,8 +43,8 @@ public function __construct( $config ) {
 			throw new Exception( 'Font Collection config options is required as a non-empty array.' );
 		}
 
-		if ( empty( $config['id'] ) || ! is_string( $config['id'] ) ) {
-			throw new Exception( 'Font Collection config ID is required as a non-empty string.' );
+		if ( empty( $config['slug'] ) || ! is_string( $config['slug'] ) ) {
+			throw new Exception( 'Font Collection config slug is required as a non-empty string.' );
 		}
 
 		if ( empty( $config['name'] ) || ! is_string( $config['name'] ) ) {
@@ -66,14 +66,14 @@ public function __construct( $config ) {
 	 * @return array {
 	 *     An array of font collection config.
 	 *
-	 *     @type string $id          The font collection's unique ID.
+	 *     @type string $slug        The font collection's unique slug.
 	 *     @type string $name        The font collection's name.
 	 *     @type string $description The font collection's description.
 	 * }
 	 */
 	public function get_config() {
 		return array(
-			'id'          => $this->config['id'],
+			'slug'        => $this->config['slug'],
 			'name'        => $this->config['name'],
 			'description' => $this->config['description'] ?? '',
 		);
@@ -90,7 +90,7 @@ public function get_config() {
 	 * @return array {
 	 *     An array of font collection config and data.
 	 *
-	 *     @type string $id          The font collection's unique ID.
+	 *     @type string $slug          The font collection's unique ID.
 	 *     @type string $name        The font collection's name.
 	 *     @type string $description The font collection's description.
 	 *     @type array  $data        The font collection's data as a PHP array.
diff --git a/lib/experimental/fonts/font-library/class-wp-font-library.php b/lib/experimental/fonts/font-library/class-wp-font-library.php
index 01ee702673e57b..fd36f6ba073c4f 100644
--- a/lib/experimental/fonts/font-library/class-wp-font-library.php
+++ b/lib/experimental/fonts/font-library/class-wp-font-library.php
@@ -63,11 +63,11 @@ public static function get_expected_font_mime_types_per_php_version( $php_versio
 	 */
 	public static function register_font_collection( $config ) {
 		$new_collection = new WP_Font_Collection( $config );
-		if ( self::is_collection_registered( $config['id'] ) ) {
+		if ( self::is_collection_registered( $config['slug'] ) ) {
 			$error_message = sprintf(
-				/* translators: %s: Font collection id. */
-				__( 'Font collection with id: "%s" is already registered.', 'default' ),
-				$config['id']
+				/* translators: %s: Font collection slug. */
+				__( 'Font collection with slug: "%s" is already registered.', 'default' ),
+				$config['slug']
 			);
 			_doing_it_wrong(
 				__METHOD__,
@@ -76,7 +76,7 @@ public static function register_font_collection( $config ) {
 			);
 			return new WP_Error( 'font_collection_registration_error', $error_message );
 		}
-		self::$collections[ $config['id'] ] = $new_collection;
+		self::$collections[ $config['slug'] ] = $new_collection;
 		return $new_collection;
 	}
 
@@ -85,20 +85,20 @@ public static function register_font_collection( $config ) {
 	 *
 	 * @since 6.5.0
 	 *
-	 * @param string $collection_id Font collection ID.
+	 * @param string $collection_slug Font collection slug.
 	 * @return bool True if the font collection was unregistered successfully and false otherwise.
 	 */
-	public static function unregister_font_collection( $collection_id ) {
-		if ( ! self::is_collection_registered( $collection_id ) ) {
+	public static function unregister_font_collection( $slug ) {
+		if ( ! self::is_collection_registered( $slug ) ) {
 			_doing_it_wrong(
 				__METHOD__,
-				/* translators: %s: Font collection id. */
-				sprintf( __( 'Font collection "%s" not found.', 'default' ), $collection_id ),
+				/* translators: %s: Font collection slug. */
+				sprintf( __( 'Font collection "%s" not found.', 'default' ), $slug ),
 				'6.5.0'
 			);
 			return false;
 		}
-		unset( self::$collections[ $collection_id ] );
+		unset( self::$collections[ $slug ] );
 		return true;
 	}
 
@@ -107,11 +107,11 @@ public static function unregister_font_collection( $collection_id ) {
 	 *
 	 * @since 6.5.0
 	 *
-	 * @param string $collection_id Font collection ID.
+	 * @param string $slug Font collection slug.
 	 * @return bool True if the font collection is registered and false otherwise.
 	 */
-	private static function is_collection_registered( $collection_id ) {
-		return array_key_exists( $collection_id, self::$collections );
+	private static function is_collection_registered( $slug ) {
+		return array_key_exists( $slug, self::$collections );
 	}
 
 	/**
@@ -130,12 +130,12 @@ public static function get_font_collections() {
 	 *
 	 * @since 6.5.0
 	 *
-	 * @param string $id Font collection id.
+	 * @param string $slug Font collection slug.
 	 * @return array List of font collections.
 	 */
-	public static function get_font_collection( $id ) {
-		if ( array_key_exists( $id, self::$collections ) ) {
-			return self::$collections[ $id ];
+	public static function get_font_collection( $slug ) {
+		if ( array_key_exists( $slug, self::$collections ) ) {
+			return self::$collections[ $slug ];
 		}
 		return new WP_Error( 'font_collection_not_found', 'Font collection not found.' );
 	}
diff --git a/lib/experimental/fonts/font-library/class-wp-rest-font-collections-controller.php b/lib/experimental/fonts/font-library/class-wp-rest-font-collections-controller.php
index 0efd56f61d43ea..c7595a56413b9b 100644
--- a/lib/experimental/fonts/font-library/class-wp-rest-font-collections-controller.php
+++ b/lib/experimental/fonts/font-library/class-wp-rest-font-collections-controller.php
@@ -50,7 +50,7 @@ public function register_routes() {
 
 		register_rest_route(
 			$this->namespace,
-			'/' . $this->rest_base . '/(?P<id>[\/\w-]+)',
+			'/' . $this->rest_base . '/(?P<slug>[\/\w-]+)',
 			array(
 				array(
 					'methods'             => WP_REST_Server::READABLE,
@@ -70,8 +70,8 @@ public function register_routes() {
 	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
 	 */
 	public function get_font_collection( $request ) {
-		$id         = $request->get_param( 'id' );
-		$collection = WP_Font_Library::get_font_collection( $id );
+		$slug       = $request->get_param( 'slug' );
+		$collection = WP_Font_Library::get_font_collection( $slug );
 		// If the collection doesn't exist returns a 404.
 		if ( is_wp_error( $collection ) ) {
 			$collection->add_data( array( 'status' => 404 ) );
diff --git a/lib/experimental/fonts/font-library/font-library.php b/lib/experimental/fonts/font-library/font-library.php
index c2545171dace03..d1ad8e1447ad9c 100644
--- a/lib/experimental/fonts/font-library/font-library.php
+++ b/lib/experimental/fonts/font-library/font-library.php
@@ -76,7 +76,7 @@ function wp_unregister_font_collection( $collection_id ) {
 }
 
 $default_font_collection = array(
-	'id'          => 'default-font-collection',
+	'slug'        => 'default-font-collection',
 	'name'        => 'Google Fonts',
 	'description' => __( 'Add from Google Fonts. Fonts are copied to and served from your site.', 'gutenberg' ),
 	'src'         => 'https://s.w.org/images/fonts/16.7/collections/google-fonts-with-preview.json',
diff --git a/phpunit/tests/fonts/font-library/wpFontCollection/__construct.php b/phpunit/tests/fonts/font-library/wpFontCollection/__construct.php
index 21f529d71a297f..380226ee8af8a3 100644
--- a/phpunit/tests/fonts/font-library/wpFontCollection/__construct.php
+++ b/phpunit/tests/fonts/font-library/wpFontCollection/__construct.php
@@ -17,7 +17,7 @@ public function test_should_initialize_data() {
 		$property->setAccessible( true );
 
 		$config          = array(
-			'id'          => 'my-collection',
+			'slug'        => 'my-collection',
 			'name'        => 'My Collection',
 			'description' => 'My collection description',
 			'src'         => 'my-collection-data.json',
@@ -55,7 +55,7 @@ public function data_should_throw_exception() {
 					'description' => 'My collection description',
 					'src'         => 'my-collection-data.json',
 				),
-				'Font Collection config ID is required as a non-empty string.',
+				'Font Collection config slug is required as a non-empty string.',
 			),
 
 			'no config'                       => array(
@@ -80,7 +80,7 @@ public function data_should_throw_exception() {
 
 			'missing src'                     => array(
 				array(
-					'id'          => 'my-collection',
+					'slug'        => 'my-collection',
 					'name'        => 'My Collection',
 					'description' => 'My collection description',
 				),
diff --git a/phpunit/tests/fonts/font-library/wpFontCollection/getConfig.php b/phpunit/tests/fonts/font-library/wpFontCollection/getConfig.php
index 03f59b6a1a6ebc..5f1f082297d418 100644
--- a/phpunit/tests/fonts/font-library/wpFontCollection/getConfig.php
+++ b/phpunit/tests/fonts/font-library/wpFontCollection/getConfig.php
@@ -34,39 +34,39 @@ public function data_should_get_config() {
 		return array(
 			'with a file' => array(
 				'config'        => array(
-					'id'          => 'my-collection',
+					'slug'        => 'my-collection',
 					'name'        => 'My Collection',
 					'description' => 'My collection description',
 					'src'         => $mock_file,
 				),
 				'expected_data' => array(
-					'id'          => 'my-collection',
+					'slug'        => 'my-collection',
 					'name'        => 'My Collection',
 					'description' => 'My collection description',
 				),
 			),
 			'with a url'  => array(
 				'config'        => array(
-					'id'          => 'my-collection-with-url',
+					'slug'        => 'my-collection-with-url',
 					'name'        => 'My Collection with URL',
 					'description' => 'My collection description',
 					'src'         => 'https://localhost/fonts/mock-font-collection.json',
 				),
 				'expected_data' => array(
-					'id'          => 'my-collection-with-url',
+					'slug'        => 'my-collection-with-url',
 					'name'        => 'My Collection with URL',
 					'description' => 'My collection description',
 				),
 			),
 			'with data'   => array(
 				'config'        => array(
-					'id'          => 'my-collection',
+					'slug'        => 'my-collection',
 					'name'        => 'My Collection',
 					'description' => 'My collection description',
 					'data'        => array( 'this is mock data' => true ),
 				),
 				'expected_data' => array(
-					'id'          => 'my-collection',
+					'slug'        => 'my-collection',
 					'name'        => 'My Collection',
 					'description' => 'My collection description',
 				),
diff --git a/phpunit/tests/fonts/font-library/wpFontCollection/getConfigAndData.php b/phpunit/tests/fonts/font-library/wpFontCollection/getConfigAndData.php
index a71928193c9aa3..885b0a0b9036cb 100644
--- a/phpunit/tests/fonts/font-library/wpFontCollection/getConfigAndData.php
+++ b/phpunit/tests/fonts/font-library/wpFontCollection/getConfigAndData.php
@@ -69,13 +69,13 @@ public function data_should_get_config_and_data() {
 		return array(
 			'with a file' => array(
 				'config'        => array(
-					'id'          => 'my-collection',
+					'slug'        => 'my-collection',
 					'name'        => 'My Collection',
 					'description' => 'My collection description',
 					'src'         => $mock_file,
 				),
 				'expected_data' => array(
-					'id'          => 'my-collection',
+					'slug'        => 'my-collection',
 					'name'        => 'My Collection',
 					'description' => 'My collection description',
 					'data'        => array( 'this is mock data' => true ),
@@ -83,13 +83,13 @@ public function data_should_get_config_and_data() {
 			),
 			'with a url'  => array(
 				'config'        => array(
-					'id'          => 'my-collection-with-url',
+					'slug'        => 'my-collection-with-url',
 					'name'        => 'My Collection with URL',
 					'description' => 'My collection description',
 					'src'         => 'https://localhost/fonts/mock-font-collection.json',
 				),
 				'expected_data' => array(
-					'id'          => 'my-collection-with-url',
+					'slug'        => 'my-collection-with-url',
 					'name'        => 'My Collection with URL',
 					'description' => 'My collection description',
 					'data'        => array(
@@ -100,13 +100,13 @@ public function data_should_get_config_and_data() {
 			),
 			'with data'   => array(
 				'config'        => array(
-					'id'          => 'my-collection',
+					'slug'        => 'my-collection',
 					'name'        => 'My Collection',
 					'description' => 'My collection description',
 					'data'        => array( 'this is mock data' => true ),
 				),
 				'expected_data' => array(
-					'id'          => 'my-collection',
+					'slug'        => 'my-collection',
 					'name'        => 'My Collection',
 					'description' => 'My collection description',
 					'data'        => array( 'this is mock data' => true ),
diff --git a/phpunit/tests/fonts/font-library/wpFontLibrary/getFontCollection.php b/phpunit/tests/fonts/font-library/wpFontLibrary/getFontCollection.php
index 00d5ca2dcb2e73..082ca892114659 100644
--- a/phpunit/tests/fonts/font-library/wpFontLibrary/getFontCollection.php
+++ b/phpunit/tests/fonts/font-library/wpFontLibrary/getFontCollection.php
@@ -14,7 +14,7 @@ class Tests_Fonts_WpFontLibrary_GetFontCollection extends WP_Font_Library_UnitTe
 
 	public function test_should_get_font_collection() {
 		$my_font_collection_config = array(
-			'id'          => 'my-font-collection',
+			'slug'        => 'my-font-collection',
 			'name'        => 'My Font Collection',
 			'description' => 'Demo about how to a font collection to your WordPress Font Library.',
 			'src'         => path_join( __DIR__, 'my-font-collection-data.json' ),
@@ -24,7 +24,7 @@ public function test_should_get_font_collection() {
 		$this->assertInstanceOf( 'WP_Font_Collection', $font_collection );
 	}
 
-	public function test_should_get_no_font_collection_if_the_id_is_not_registered() {
+	public function test_should_get_no_font_collection_if_the_slug_is_not_registered() {
 		$font_collection = WP_Font_Library::get_font_collection( 'not-registered-font-collection' );
 		$this->assertWPError( $font_collection );
 	}
diff --git a/phpunit/tests/fonts/font-library/wpFontLibrary/getFontCollections.php b/phpunit/tests/fonts/font-library/wpFontLibrary/getFontCollections.php
index 40eacba8e18c56..a405584efccc23 100644
--- a/phpunit/tests/fonts/font-library/wpFontLibrary/getFontCollections.php
+++ b/phpunit/tests/fonts/font-library/wpFontLibrary/getFontCollections.php
@@ -18,7 +18,7 @@ public function test_should_get_an_empty_list() {
 
 	public function test_should_get_mock_font_collection() {
 		$my_font_collection_config = array(
-			'id'          => 'my-font-collection',
+			'slug'        => 'my-font-collection',
 			'name'        => 'My Font Collection',
 			'description' => 'Demo about how to a font collection to your WordPress Font Library.',
 			'src'         => path_join( __DIR__, 'my-font-collection-data.json' ),
diff --git a/phpunit/tests/fonts/font-library/wpFontLibrary/registerFontCollection.php b/phpunit/tests/fonts/font-library/wpFontLibrary/registerFontCollection.php
index 2569830f6bf2aa..a7ea2870957e9d 100644
--- a/phpunit/tests/fonts/font-library/wpFontLibrary/registerFontCollection.php
+++ b/phpunit/tests/fonts/font-library/wpFontLibrary/registerFontCollection.php
@@ -14,7 +14,7 @@ class Tests_Fonts_WpFontLibrary_RegisterFontCollection extends WP_Font_Library_U
 
 	public function test_should_register_font_collection() {
 		$config     = array(
-			'id'          => 'my-collection',
+			'slug'        => 'my-collection',
 			'name'        => 'My Collection',
 			'description' => 'My Collection Description',
 			'src'         => 'my-collection-data.json',
@@ -23,20 +23,20 @@ public function test_should_register_font_collection() {
 		$this->assertInstanceOf( 'WP_Font_Collection', $collection );
 	}
 
-	public function test_should_return_error_if_id_is_missing() {
+	public function test_should_return_error_if_slug_is_missing() {
 		$config = array(
 			'name'        => 'My Collection',
 			'description' => 'My Collection Description',
 			'src'         => 'my-collection-data.json',
 		);
 		$this->expectException( 'Exception' );
-		$this->expectExceptionMessage( 'Font Collection config ID is required as a non-empty string.' );
+		$this->expectExceptionMessage( 'Font Collection config slug is required as a non-empty string.' );
 		WP_Font_Library::register_font_collection( $config );
 	}
 
 	public function test_should_return_error_if_name_is_missing() {
 		$config = array(
-			'id'          => 'my-collection',
+			'slug'        => 'my-collection',
 			'description' => 'My Collection Description',
 			'src'         => 'my-collection-data.json',
 		);
@@ -52,15 +52,15 @@ public function test_should_return_error_if_config_is_empty() {
 		WP_Font_Library::register_font_collection( $config );
 	}
 
-	public function test_should_return_error_if_id_is_repeated() {
+	public function test_should_return_error_if_slug_is_repeated() {
 		$config1 = array(
-			'id'          => 'my-collection-1',
+			'slug'        => 'my-collection-1',
 			'name'        => 'My Collection 1',
 			'description' => 'My Collection 1 Description',
 			'src'         => 'my-collection-1-data.json',
 		);
 		$config2 = array(
-			'id'          => 'my-collection-1',
+			'slug'        => 'my-collection-1',
 			'name'        => 'My Collection 2',
 			'description' => 'My Collection 2 Description',
 			'src'         => 'my-collection-2-data.json',
@@ -72,7 +72,7 @@ public function test_should_return_error_if_id_is_repeated() {
 
 		// Expects a _doing_it_wrong notice.
 		$this->setExpectedIncorrectUsage( 'WP_Font_Library::register_font_collection' );
-		// Try to register a second collection with same id.
+		// Try to register a second collection with same slug.
 		$collection2 = WP_Font_Library::register_font_collection( $config2 );
 		$this->assertWPError( $collection2, 'A WP_Error should be returned.' );
 	}
diff --git a/phpunit/tests/fonts/font-library/wpFontLibrary/unregisterFontCollection.php b/phpunit/tests/fonts/font-library/wpFontLibrary/unregisterFontCollection.php
index e6e16956814fb4..3c19a1d2089e7a 100644
--- a/phpunit/tests/fonts/font-library/wpFontLibrary/unregisterFontCollection.php
+++ b/phpunit/tests/fonts/font-library/wpFontLibrary/unregisterFontCollection.php
@@ -15,7 +15,7 @@ class Tests_Fonts_WpFontLibrary_UnregisterFontCollection extends WP_Font_Library
 	public function test_should_unregister_font_collection() {
 		// Registers two mock font collections.
 		$config = array(
-			'id'          => 'mock-font-collection-1',
+			'slug'        => 'mock-font-collection-1',
 			'name'        => 'Mock Collection to be unregistered',
 			'description' => 'A mock font collection to be unregistered.',
 			'src'         => 'my-collection-data.json',
@@ -23,7 +23,7 @@ public function test_should_unregister_font_collection() {
 		WP_Font_Library::register_font_collection( $config );
 
 		$config = array(
-			'id'          => 'mock-font-collection-2',
+			'slug'        => 'mock-font-collection-2',
 			'name'        => 'Mock Collection',
 			'description' => 'A mock font collection.',
 			'src'         => 'my-mock-data.json',
diff --git a/phpunit/tests/fonts/font-library/wpRestFontCollectionsController/getFontCollection.php b/phpunit/tests/fonts/font-library/wpRestFontCollectionsController/getFontCollection.php
index 94e7daaa166345..c9d003389997b4 100644
--- a/phpunit/tests/fonts/font-library/wpRestFontCollectionsController/getFontCollection.php
+++ b/phpunit/tests/fonts/font-library/wpRestFontCollectionsController/getFontCollection.php
@@ -25,7 +25,7 @@ public function set_up() {
 		add_filter( 'pre_http_request', array( $this, 'mock_request' ), 10, 3 );
 
 		$config_with_file = array(
-			'id'          => 'one-collection',
+			'slug'        => 'one-collection',
 			'name'        => 'One Font Collection',
 			'description' => 'Demo about how to a font collection to your WordPress Font Library.',
 			'src'         => $mock_file,
@@ -33,7 +33,7 @@ public function set_up() {
 		wp_register_font_collection( $config_with_file );
 
 		$config_with_url = array(
-			'id'          => 'collection-with-url',
+			'slug'        => 'collection-with-url',
 			'name'        => 'Another Font Collection',
 			'description' => 'Demo about how to a font collection to your WordPress Font Library.',
 			'src'         => 'https://wordpress.org/fonts/mock-font-collection.json',
@@ -42,7 +42,7 @@ public function set_up() {
 		wp_register_font_collection( $config_with_url );
 
 		$config_with_non_existing_file = array(
-			'id'          => 'collection-with-non-existing-file',
+			'slug'        => 'collection-with-non-existing-file',
 			'name'        => 'Another Font Collection',
 			'description' => 'Demo about how to a font collection to your WordPress Font Library.',
 			'src'         => '/home/non-existing-file.json',
@@ -51,7 +51,7 @@ public function set_up() {
 		wp_register_font_collection( $config_with_non_existing_file );
 
 		$config_with_non_existing_url = array(
-			'id'          => 'collection-with-non-existing-url',
+			'slug'        => 'collection-with-non-existing-url',
 			'name'        => 'Another Font Collection',
 			'description' => 'Demo about how to a font collection to your WordPress Font Library.',
 			'src'         => 'https://non-existing-url-1234x.com.ar/fake-path/missing-file.json',
diff --git a/phpunit/tests/fonts/font-library/wpRestFontCollectionsController/getFontCollections.php b/phpunit/tests/fonts/font-library/wpRestFontCollectionsController/getFontCollections.php
index 224dab07cf0b7a..0a8d24e8f392ba 100644
--- a/phpunit/tests/fonts/font-library/wpRestFontCollectionsController/getFontCollections.php
+++ b/phpunit/tests/fonts/font-library/wpRestFontCollectionsController/getFontCollections.php
@@ -27,7 +27,7 @@ public function test_get_font_collections() {
 
 		// Add a font collection.
 		$config = array(
-			'id'          => 'my-font-collection',
+			'slug'        => 'my-font-collection',
 			'name'        => 'My Font Collection',
 			'description' => 'Demo about how to a font collection to your WordPress Font Library.',
 			'src'         => $mock_file,
@@ -39,7 +39,7 @@ public function test_get_font_collections() {
 		$data     = $response->get_data();
 		$this->assertSame( 200, $response->get_status(), 'The response status is not 200.' );
 		$this->assertCount( 1, $data, 'The response data is not an array with one element.' );
-		$this->assertArrayHasKey( 'id', $data[0], 'The response data does not have the key with the collection ID.' );
+		$this->assertArrayHasKey( 'slug', $data[0], 'The response data does not have the key with the collection slug.' );
 		$this->assertArrayHasKey( 'name', $data[0], 'The response data does not have the key with the collection name.' );
 	}
 }
diff --git a/phpunit/tests/fonts/font-library/wpRestFontCollectionsController/registerRoutes.php b/phpunit/tests/fonts/font-library/wpRestFontCollectionsController/registerRoutes.php
index c2c019fa70a022..fb100a400fb4cf 100644
--- a/phpunit/tests/fonts/font-library/wpRestFontCollectionsController/registerRoutes.php
+++ b/phpunit/tests/fonts/font-library/wpRestFontCollectionsController/registerRoutes.php
@@ -16,9 +16,9 @@ class Tests_Fonts_WPRESTFontCollectionsController_RegisterRoutes extends WP_Unit
 	public function test_register_routes() {
 		$routes = rest_get_server()->get_routes();
 		$this->assertCount( 1, $routes['/wp/v2/font-collections'], 'Rest server has not the collections path initialized.' );
-		$this->assertCount( 1, $routes['/wp/v2/font-collections/(?P<id>[\/\w-]+)'], 'Rest server has not the collection path initialized.' );
+		$this->assertCount( 1, $routes['/wp/v2/font-collections/(?P<slug>[\/\w-]+)'], 'Rest server has not the collection path initialized.' );
 
 		$this->assertArrayHasKey( 'GET', $routes['/wp/v2/font-collections'][0]['methods'], 'Rest server has not the GET method for collections intialized.' );
-		$this->assertArrayHasKey( 'GET', $routes['/wp/v2/font-collections/(?P<id>[\/\w-]+)'][0]['methods'], 'Rest server has not the GET method for collection intialized.' );
+		$this->assertArrayHasKey( 'GET', $routes['/wp/v2/font-collections/(?P<slug>[\/\w-]+)'][0]['methods'], 'Rest server has not the GET method for collection intialized.' );
 	}
 }