numeric jail name in jail.conf

[Nicolas de Bari Embriz Garcia Rojas]

Hi, when using a numeric names for a jails something like:

10 {
    exec.start = "/bin/sh /etc/rc";
    exec.stop = "/bin/sh /etc/rc.shutdown";
    ....
}

20 {
    exec.start = "/bin/sh /etc/rc";
    exec.stop = "/bin/sh /etc/rc.shutdown";
    ....
}

the name (numeric) becomes the jail ID when, therefore when I type a jls
command i see the  10,and 20 as the jails ID's,

My question is, is this the proper way to explicitly set the id when
using jail.conf ?

For me, this as been working fine and I can match the jail ids to use
rctl on every reboot, but just want to be sure if this is the correct
way of doing it.

thanks in advance.