WordPress at a glance
filter is not described

register filter-hook . WP 1.5.0

Filters the HTML link to the Registration or Admin page.

Users are sent to the admin page if logged-in, or the registration page if enabled and logged-out.

Usage

add_filter( 'register', 'filter_function_name_7367' );
function filter_function_name_7367( $link ){
	// filter...

	return $link;
}
$link(string)
The HTML code for the link to the Registration or Admin page.

Where the hook is called

wp_register()
register
wp-includes/general-template.php 546
$link = apply_filters( 'register', $link );
wp-login.php 602
echo apply_filters( 'register', $registration_url );
wp-login.php 727
echo apply_filters( 'register', $registration_url );
wp-login.php 1041
echo apply_filters( 'register', $registration_url );

Where the hook is used (in WP core)

Does not used.