How do I check minimum OS patch levels needed for Calibre?

Version 1

    How to find out which OS patches have been installed:

     

    For Linux Red Hat:
            cat /etc/redhat-release

     

    For Linux SUSE:
             cat /etc/SuSE-release

     

    For Solaris:
            uname -a

     

            For more details about installed patches use:
            /bin/showrev -p | grep <patch_name>

    Minimum patch levels for all operating systems are listed in the "Calibre Administrator's Guide," which is in the Calibre bookcase.