ncludes/category.php ` |  Retrieves all post tags.   
[ WP_Image_Editor_Imagick::_save() ](https://developer.wordpress.org/reference/classes/wp_image_editor_imagick/_save/) ` wp-includes/class-wp-image-editor-imagick.php ` |   
[ get_categories() ](https://developer.wordpress.org/reference/functions/get_categories/) ` wp-includes/category.php ` |  Retrieves a list of category objects.   
[ wp_start_object_cache() ](https://developer.wordpress.org/reference/functions/wp_start_object_cache/) ` wp-includes/load.php ` |  Starts the WordPress object cache.   
[ wp_debug_mode() ](https://developer.wordpress.org/reference/functions/wp_debug_mode/) ` wp-includes/load.php ` |  Sets PHP error reporting based on WordPress debug settings.   
[ WP_Http_Cookie::getHeaderValue() ](https://developer.wordpress.org/reference/classes/wp_http_cookie/getheadervalue/) ` wp-includes/class-wp-http-cookie.php ` |  Convert cookie name and value back to header string.   
[ WP_Http_Encoding::accept_encoding() ](https://developer.wordpress.org/reference/classes/wp_http_encoding/accept_encoding/) ` wp-includes/class-wp-http-encoding.php ` |  What encoding types to accept and their priority values.   
[ WP_HTTP_Proxy::send_through_proxy() ](https://developer.wordpress.org/reference/classes/wp_http_proxy/send_through_proxy/) ` wp-includes/class-wp-http-proxy.php ` |  Determines whether the request should be sent through a proxy.   
[ WP_Http_Curl::test() ](https://developer.wordpress.org/reference/classes/wp_http_curl/test/) ` wp-includes/class-wp-http-curl.php ` |  Determines whether this class can be used for retrieving a URL.   
[ WP_Http::block_request() ](https://developer.wordpress.org/reference/classes/wp_http/block_request/) ` wp-includes/class-wp-http.php ` |  Determines whether an HTTP API request to the given URL should be blocked.   
[ WP_Http_Streams::request() ](https://developer.wordpress.org/reference/classes/wp_http_streams/request/) ` wp-includes/class-wp-http-streams.php ` |  Send a HTTP request to a URI using PHP Streams.   
[ WP_Http_Streams::test() ](https://developer.wordpress.org/reference/classes/wp_http_streams/test/) ` wp-includes/class-wp-http-streams.php ` |  Determines whether this class can be used for retrieving a URL.   
[ WP_Http_Curl::request() ](https://developer.wordpress.org/reference/classes/wp_http_curl/request/) ` wp-includes/class-wp-http-curl.php ` |  Send a HTTP request to a URI using cURL extension.   
[ WP_Http::_dispatch_request() ](https://developer.wordpress.org/reference/classes/wp_http/_dispatch_request/) ` wp-includes/class-wp-http.php ` |  Dispatches a HTTP request to a supporting transport.   
[ WP_Http::request() ](https://developer.wordpress.org/reference/classes/wp_http/request/) ` wp-includes/class-wp-http.php ` |  Send an HTTP request to a URI.   
[ wp_allowed_protocols() ](https://developer.wordpress.org/reference/functions/wp_allowed_protocols/) ` wp-includes/functions.php ` |  Retrieves a list of protocols to allow in HTML attributes.   
[ wp_checkdate() ](https://developer.wordpress.org/reference/functions/wp_checkdate/) ` wp-includes/functions.php ` |  Tests if the supplied date is valid for the Gregorian calendar.   
[ wp_auth_check_load() ](https://developer.wordpress.org/reference/functions/wp_auth_check_load/) ` wp-includes/functions.php ` |  Loads the auth check for monitoring whether the user is still logged in.   
[ wp_auth_check_html() ](https://developer.wordpress.org/reference/functions/wp_auth_check_html/) ` wp-includes/functions.php ` |  Outputs the HTML that shows the wp-login dialog when the user is no longer logged in.   
[ get_file_data() ](https://developer.wordpress.org/reference/functions/get_file_data/) ` wp-includes/functions.php ` |  Retrieves metadata from a file.   
[ _deprecated_function() ](https://developer.wordpress.org/reference/functions/_deprecated_function/) ` wp-includes/functions.php ` |  Marks a function as deprecated and inform when it has been used.   
[ _dep