Explanation: Ubuntu <%= scope.lookupvar('::lsbdistcodename') %> security
Package: *
Pin: release o=Ubuntu,a=<%= scope.lookupvar('::lsbdistcodename') %>-security
Pin-Priority: 990

Explanation: Ubuntu <%= scope.lookupvar('::lsbdistcodename') %> updates
Package: *
Pin: release o=Ubuntu,a=<%= scope.lookupvar('::lsbdistcodename') %>-updates
Pin-Priority: 980

Explanation: Ubuntu <%= scope.lookupvar('::lsbdistcodename') %>
Package: *
Pin: release o=Ubuntu,a=<%= scope.lookupvar('::lsbdistcodename') %>
Pin-Priority: 970

Explanation: Ubuntu backports
Package: *
Pin: release a=<%= scope.lookupvar('::lsbdistcodename') %>-backports
Pin-Priority: 200

Explanation: Ubuntu <%= scope.lookupvar('apt::next_release') %>
Package: *
Pin: release o=Ubuntu,a=<%= scope.lookupvar('apt::next_release') %>
Pin-Priority: 2

Explanation: Ubuntu fallback
Package: *
Pin: release o=Ubuntu
Pin-Priority: -10