string unstable nos avisos de upgrade para jessie

[Fred Maranhão <fred.maranhao@gmail.com>]

Caros,

estou começando a migração para jessie. mas notei uma coisa estranha.

durante um apt-get upgrade, aparecem avisos quando tem uma mudança
mais drática num pacote. por exemplo:

=====================================
initramfs-tools (0.119) unstable; urgency=medium

  * The initramfs will now run fsck on the root filesystem before
    mounting it.  If the chosen init program is systemd and there is a
    separate /usr filesystem, it will also fsck and mount /usr.
  * If /usr is a separate filesystem on a RAID device and the INITRDSTART
    setting in /etc/default/mdadm is not 'all', you will need to change it
    to include that device.
  * If /usr is a separate filesystem on an LVM logical volume, and the
    line for /usr in /etc/fstab specifies the device by UUID or LABEL,
    you must change this line to specify the device using the format
    /dev/mapper/VG-LV or /dev/VG/LV.
  * It is no longer possible to bind-mount the /usr filesystem.
  * If the RTC (real time clock) is set to local time and the local time is
    ahead of UTC, e2fsck will print a warning during boot about the time
    changing backward (bug #767040).  You can disable this by putting the
    following lines in /etc/e2fsck.conf:
        [options]
        broken_system_clock=1

 -- Ben Hutchings <ben@decadent.org.uk>  Mon, 13 Apr 2015 01:00:21 +0100

coreutils (8.23-1) unstable; urgency=low

  GNU coreutils package now includes the `realpath' command that used to
  be found in a separate `realpath' package.

  Even though the GNU version provides all the features of the old Debian
  version, the behaviour is a bit different, namely:

    * GNU `realpath' and `realpath -s' commands require all but the
      last path components to exist

  whereas:

    * Debian version of `realpath' required all the path components to exist;
    * Debian version of `realpath -s' required no path components to exist.

  To get the old behaviour in GNU `realpath' an additional option needs
  to be used:

       Old Debian realpath       New GNU coreutils realpath
     -----------------------    ----------------------------
      realpath    file(s)    =>    realpath -e    file(s)
      realpath -s file(s)    =>    realpath -s -m file(s)

 -- Robert Luberda <robert@debian.org>  Sun, 31 Aug 2014 16:08:14 +0200

=====================================

a minha dúvida é. o que significa este 'unstable' no cabeçalho:

initramfs-tools (0.119) unstable; urgency=medium
coreutils (8.23-1) unstable; urgency=low

não deveria ser stable? ou este nome não tem a ver com a versão do debian?