CentOS - May 2010 - Number and colon precedes some package names in yum.log

What is the meaning of the "4:", "2:", "30:" and
"1:" prefixes for the
following entries in yum.log?  Most entries in yum.log don't have
them.

grep "Installed: [0-9]*:" /var/log/yum.log
May 07 16:45:53 Installed: 4:perl-5.8.8-27.el5.i386
May 07 16:58:21 Installed: 2:xinetd-2.3.14-10.el5.i386
May 07 17:03:43 Installed: 30:bind-libs-9.3.6-4.P1.el5_4.2.i386
May 07 17:03:43 Installed: 30:bind-utils-9.3.6-4.P1.el5_4.2.i386
May 07 17:12:28 Installed: 1:telnet-0.17-39.el5.i386

On Mon, May 10, 2010 at 5:24 PM, Keith Christian
<keith1christian at gmail.com> wrote:
> What is the meaning of the "4:", "2:", "30:"
and "1:" prefixes for the
> following entries in yum.log? ?Most entries in yum.log don't have
> them.
That's the "Epoch" in the package.

An rpm package is characterised by NEVR, which is

Name
Epoch
Version
Release.

Cheers,

Ralph