You know what really grinds my gears?  For the last 3 major versions of RHEL, Red Hat has changed how the redhat-release packages work.  So for each version I’ve had to write more code to deduce what version a specific RHEL/CentOS/Fedora machine is.

RHEL 4 has the AS/ES/WS flavors.  RHEL 5 has Client and Server flavors.  So the redhat-release package has a version like 5Client.  Okay extra code to deal with the Client and Server strings.  RHEL 6 (yet to be released) has moved the redhat-release packages to redhat-release-server and redhat-release-workstation.  There is no more Client flag.  So yet more code.  Deducing the version of Fedora has yet to change, however.

You know your packages contain redundant information when:

$ rpm -q --qf '%{epoch}:%{name}-%{version}-%{release}.%{arch}\n' \
   redhat-release-workstation
(none):redhat-release-workstation-5.90Workstation-6.0.0.32.el6.x86_64