WordPress at Your Fingertips
action is not described

wp_body_open action-hook . WP 5.2.0

Triggered after the opening body tag.

Usage

add_action( 'wp_body_open', 'action_function_name_1602' );
function action_function_name_1602(){
	// action...
}

Where the hook is called

wp_body_open()
wp_body_open
wp-includes/general-template.php 3047
do_action( 'wp_body_open' );

Where in WP core the hook is used WordPress

wp-includes/default-filters.php 614
add_action( 'wp_body_open', 'wp_admin_bar_render', 0 );