There are numerous yum plugins. You can search for which are available.
What does yum-plugin-verify do?
"This plugin adds the commands verify, verify-all and verify-rpm. There are also a couple of options. This command works like rpm -V, to verify your installation." [yum info yum-plugin-verify]
For more information about each commands, run 'yum --help'
What does yum-plugin-versionlock do?
"This plugin takes a set of name/versions for packages and excludes all other versions of those packages (including optionally following obsoletes). This allows you to protect packages from being updated by newer versions, for example." [yum info yum-plugin-versionlock]
The yum-plugin-versionlock uses the /etc/yum/pluginconf.d/versionlock.list to lock down specific packages.
The following format is used for locking down. See /usr/share/doc/yum-plugin-versionlock-*/README.