preferences

# < 0      - Never install Package
# 1:100    - Only install if not installed in any other version
# 100:500  - Only install if there is not a newer version installed and there is
#            no version in higher ranked distro
# 500:990  - Install package if there is not a target release version or newer
#            version already installed
# 990:1000 - Always install if there is not a newer version of the package already installed
# > 1000   - Always install. Even if it means to downgrade.


Package: *
Pin: release n=stretch
Pin-Priority: 900

Package: *
Pin: release n=stretch-backports
Pin-Priority: 900

Package: *
Pin: release n=stretch-updates
Pin-Priority: 900


Package: *
Pin: release n=stretch-proposed-updates
Pin-Priority: 700

Package: *
Pin: release a=stable
Pin-Priority: 900


Package: *
Pin: release a=testing
Pin-Priority: 400

Package: *
Pin: release a=unstable
Pin-Priority: -10