WordPress at a glance
action is not described

page_attributes_meta_box_template action-hook . WP 4.4.0

Fires immediately after the label inside the 'Template' section of the 'Page Attributes' meta box.

Usage

add_action( 'page_attributes_meta_box_template', 'action_function_name_5472', 10, 2 );
function action_function_name_5472( $template, $post ){
	// action...
}
$template(string)
The template used for the current post.
$post(WP_Post)
The current post.

Where the hook is called

page_attributes_meta_box()
page_attributes_meta_box_template
wp-admin/includes/meta-boxes.php 880
do_action( 'page_attributes_meta_box_template', $template, $post );

Where the hook is used (in WP core)

Does not used.