WordPress at a glance
filter is not described

wpmu_signup_user_notification_subject filter-hook . WP MU

Filters the subject of the notification email of new user signup.

Usage

add_filter( 'wpmu_signup_user_notification_subject', 'filter_function_name_7394', 10, 6 );
function filter_function_name_7394( $subject, $user_login, $user_email, $key, $meta, $meta ){
	// filter...

	return $subject;
}
$subject(string)
Subject of the notification email.
$user_login(string)
User login name.
$user_email(string)
User email address.
$key(string)
Activation key created in wpmu_signup_user().
$meta(array)
Signup meta data.
Default: empty array
$meta
-

Notes

  • Since MU (3.0.0)

Where the hook is called

wpmu_signup_user_notification()
wpmu_signup_user_notification_subject
wp-includes/ms-functions.php 1010-1014
apply_filters( 'wpmu_signup_user_notification_subject',
	/* translators: New user notification email subject. 1: Network name, 2: New user login */
	_x( '[%1$s] Activate %2$s', 'New user notification email subject' ),
	$user_login, $user_email, $key, $meta
),

Where the hook is used (in WP core)

Does not used.