[CentOS] chkconfig question

Fri Dec 13 22:00:06 UTC 2013
Larry Martell <larry.martell at gmail.com>

In the docs for chkconfig it says:

<startlevellist> is a list of the runlevels for which the service
should be started by default. Only services which are really required
for a vital system should define runlevels here. If no runlevels are
defined, a - should be used in place of the runlevels list.

and then:

More commonly, the service is off by default on all runlevels, which
looks like this:

# chkconfig: - 20 80

But services with a chkconfig entry like that are started at boot time
(e.g. mysql, httpd). So when do they get started?