Cookies without fixed lifetimes or expiration dates are known as non-persistent, or "session" cookies, meaning they last only as long as the
browser session, and poof away when the browser closes. Cookies with expiration dates, "persistent" cookies, are stored/persisted until those
dates.
Non-persistent cookies should be used for the management of logged-in sessions on web sites. To make a cookie non-persistent, simply omit the
expires attribute.
This rule raises an issue when expires is set for a session cookie, either programmatically or via configuration, such as
session.cookie_lifetime.
