wp_register( string $before = '<li>', string $after = '</li>', bool $echo = true )
Display the Registration or Admin link.
Example
<?php wp_register('', ''); ?>
// When not logged in the following HTML is produced:
<a href="http://www.example.com/wp-login.php?action=register">Register</a>
// When logged in the following HTML is produced:
<a href="http://www.example.com/wp-admin/">Site Admin</a>