WordPress at a glance
filter is not described

signup_site_meta filter-hook . WP 4.8.0

Filters the metadata for a site signup.

The metadata will be serialized prior to storing it in the database.

Usage

add_filter( 'signup_site_meta', 'filter_function_name_6311', 10, 7 );
function filter_function_name_6311( $meta, $domain, $path, $title, $user, $user_email, $key ){
	// filter...

	return $meta;
}
$meta(array)
Signup meta data.
Default: empty array
$domain(string)
The requested domain.
$path(string)
The requested path.
$title(string)
The requested site title.
$user(string)
The user's requested login name.
$user_email(string)
The user's email address.
$key(string)
The user's activation key.

Where the hook is called

wpmu_signup_blog()
wp-includes/ms-functions.php 726
$meta = apply_filters( 'signup_site_meta', $meta, $domain, $path, $title, $user, $user_email, $key );

Where the hook is used (in WP core)

Does not used.