Leading number in package names when updating with yum

[Bruno Wolff III]

On Wed, Feb 17, 2010 at 09:02:26 +0100,
  "Erik P. Olsen" <epodata at gmail.com> wrote:
> On 17/02/10 08:49, Bruno Wolff III wrote:
> > On Wed, Feb 17, 2010 at 08:26:43 +0100,
> >    Joachim Backes<joachim.backes at rhrk.uni-kl.de>  wrote:
> >> Hi all,
> >>
> >> can somebody explain what the leading number in some package names
> >> means when running "yum update", for example
> >>
> >> Feb 17 07:25:19 Updated: 1:openoffice.org-calc-3.1.1-19.26.fc12.i686
> >
> > It's the epoch.
> 
> Which is?

It's a super version number. Typically you use it when you need to go
backwards in version number because an update was bad, but you want the
older version to be seen as newer so that tools will see it as an update.
Generally its use is avoided as it can cause confusion.