When is the wp-settings-[time] cookie generated?

I created a custom plugin for login and registration forms. When I log in for a new user, 4 cookies are set : PHPSESSID, wordpress_test_cookie, wordpress_logged_in_, and 2 wordpress_sec_ .

But I don't have wp-settings- and wp-settings-time-. However my admin account has these cookies.

I can't find a wordpress documentation that explain which function set these cookies. It is just said :

Without plugins installed, WordPress sets the following cookies:

• wordpress_[hash]
• wordpress_logged_in_[hash]
• wordpress_test_cookie
• wp-settings-{time}-[UID]

I don't use setcookie at the moment .

The functions I use to allow him to access his account :

wp_clear_auth_cookie();
wp_set_current_user($info-ID, $username);  
wp_set_auth_cookie( $info-ID, true, is_ssl() );