WordPress at a glance
action is not described

wp_loaded action-hook . WP 3.0.0

This hook is fired once WP, all plugins, and the theme are fully loaded and instantiated.

Ajax requests should use wp-admin/admin-ajax.php. admin-ajax.php can handle requests for users not logged in.

Usage

add_action( 'wp_loaded', 'action_function_name_4215' );
function action_function_name_4215(){
	// action...
}

Changelog

Since 3.0.0 Introduced.

Where the hook is called

In file: /wp-settings.php
wp_loaded
wp-settings.php 579
do_action( 'wp_loaded' );

Where in WP core the hook is used WordPress

wp-settings.php 367
add_action( 'wp_loaded', array( $this, 'wp_loaded' ) );
wp-settings.php 112
add_action( 'wp_loaded', array( $this, 'override_sidebars_widgets_for_theme_switch' ) );
wp-settings.php 1471
add_action( 'wp_loaded', array( $this, 'flush_rules' ) );
wp-settings.php 1798
add_action( 'wp_loaded', array( $this, 'flush_rules' ) );
wp-settings.php 477
add_action( 'wp_loaded', '_custom_header_background_just_in_time' );