WordPress at a glance
function is not described

add_link() WP 2.0.0

Add a link to using values provided in $_POST.

No Hooks.

Return

Int/WP_Error. Value 0 or WP_Error on failure. The link ID on success.

Usage

add_link();

Code of add link: wp-admin/includes/bookmark.php VER 5.0.3

<?php
function add_link() {
	return edit_link();
}