WordPress at a glance
action is not described

wpmu_activate_blog action-hook . WP 3.0.0

Fires immediately after a site is activated.

Usage

add_action( 'wpmu_activate_blog', 'action_function_name_2756', 10, 5 );
function action_function_name_2756( $blog_id, $user_id, $password, $signup_title, $meta ){
	// action...
}
$blog_id(int)
Blog ID.
$user_id(int)
User ID.
$password(int)
User password.
$signup_title(string)
Site title.
$meta(array)
Signup meta data. By default, contains the requested privacy setting and lang_id.

Changelog

Since 3.0.0 Introduced.

Where the hook is called

wpmu_activate_signup()
wpmu_activate_blog
wp-includes/ms-functions.php 1221
do_action( 'wpmu_activate_blog', $blog_id, $user_id, $password, $signup->title, $meta );

Where the hook is used (in WP core)

wp-includes/ms-default-filters.php 40
add_action( 'wpmu_activate_blog', 'wpmu_welcome_notification', 10, 5 );