 For a number of OS distributions, the returned distro ID value is
    *reliable*, in the sense that it is documented and that it does not change
    across releases of the distribution.

    This package maintains the following reliable distro ID values:

    ==============  =========================================
    Distro ID       Distribution
    ==============  =========================================
    "ubuntu"        Ubuntu
    "debian"        Debian
    "rhel"          RedHat Enterprise Linux
    "centos"        CentOS
    "fedora"        Fedora
    "sles"          SUSE Linux Enterprise Server
    "opensuse"      openSUSE
    "amzn"          Amazon Linux
    "arch"          Arch Linux
    "buildroot"     Buildroot
    "cloudlinux"    CloudLinux OS
    "exherbo"       Exherbo Linux
    "gentoo"        GenToo Linux
    "ibm_powerkvm"  IBM PowerKVM
    "kvmibm"        KVM for IBM z Systems
    "linuxmint"     Linux Mint
    "mageia"        Mageia
    "mandriva"      Mandriva Linux
    "parallels"     Parallels
    "pidora"        Pidora
    "raspbian"      Raspbian
    "oracle"        Oracle Linux (and Oracle Enterprise Linux)
    "scientific"    Scientific Linux
    "slackware"     Slackware
    "xenserver"     XenServer
    "openbsd"       OpenBSD
    "netbsd"        NetBSD
    "freebsd"       FreeBSD
    "midnightbsd"   MidnightBSD
    "rocky"         Rocky Linux
    "guix"          Guix System
    ==============  =========================================

    If you have a need to get distros for reliable IDs added into this set,
    or if you find that the :func:`distro.id` function returns a different
    distro ID for one of the listed distros, please create an issue in the
    `distro issue tracker`_.

    **Lookup hierarchy and transformations:**

    First, the ID is obtained from the following sources, in the specified
    order. The first available and non-empty value is used:

    * the value of the "ID" attribute of the os-release file,

    * the value of the "Distributor ID" attribute returned by the lsb_release
      command,

    * the first part of the file name of the distro release file,

    The so determined ID value then passes the following transformations,
    before it is returned by this method:

    * it is translated to lower case,

    * blanks (which should not be there anyway) are translated to underscores,

    * a normalization of the ID is performed, based upon
      `normalization tables`_. The purpose of this normalization is to ensure
      that the ID is as reliable as possible, even across incompatible changes
      in the OS distributions. A common reason for an incompatible change is
      the addition of an os-release file, or the addition of the lsb_release
      command, with ID values that differ from what was previously determined
      from the distro release file name.
    )