WordPress at a glance
function is not described

signup_nonce_check() WP 3.0.0

Process the signup nonce created in signup_nonce_fields().

No Hooks.

Return

Array.

Usage

signup_nonce_check( $result );
$result(array) (required)

Code of signup nonce check: wp-includes/ms-functions.php VER 5.0.3

<?php
function signup_nonce_check( $result ) {
	if ( !strpos( $_SERVER[ 'PHP_SELF' ], 'wp-signup.php' ) )
		return $result;

	if ( wp_create_nonce('signup_form_' . $_POST[ 'signup_form_id' ]) != $_POST['_signup_form'] )
		wp_die( __( 'Please try again.' ) );

	return $result;
}