Why yum update --advisory does not update expected packages?

Issue

• System is not updating packages through advisory and throwing error:

      # yum update --advisory RHSA-2008:0583-4
      Loading "rhnplugin" plugin
      Loading "security" plugin
      rhel-i386-server-5 100% |=========================| 1.4 kB 00:00
      Setting up Update Process
      Resolving Dependencies
      Limiting packages to security relevant ones
      Advisory "RHSA-2008:0583-4" not found applicable for this system
      No packages needed, for security, 434 available
  

• Getting error for command yum update --advisory.

• Trying to clear Errata with command # yum update --advisory AdvisoryNumber results in the following error:

  Command Line Error : advisory no such command.