Every warning has points. Some are assigned different points. If you get 4 points you will get a 2 day ban.
If you get warned again after you are unbanned but before the warning drops off. The ban time will double each time.
If you get 4 bans within a year, you will get permanently banned.
Alerts are like warnings except you don't get points.
Alerts drop off your accounts after 30 days.
Warnings after 180 days
Bans after 365 days