WordPress at a glance
action is not described

mature_blog action-hook . WP 3.1.0

Fires when the 'mature' status is added to a blog.

Usage

add_action( 'mature_blog', 'action_function_name_4093' );
function action_function_name_4093( $blog_id ){
	// action...
}
$blog_id(int)
Blog ID.

Where the hook is called

update_blog_details()
update_blog_status()
wp-includes/ms-blogs.php 348
do_action( 'mature_blog', $blog_id );
wp-includes/ms-blogs.php 1034
do_action( 'mature_blog', $blog_id );

Where the hook is used (in WP core)

Does not used.