Service levels are defined in Fedora in Product Definition Center which only uses
it to lock a dist-git branch and a build in tag in Koji. An exact enumeration
of semantics of service level names was never defined.

Service levels in Red Hat Enterprise Linux are definined on Application
Stream Life Cycle page of Customar Portal. There is only one type of service
level and that is end of life.

YAML has the service levels as an automatic field filled by MBS. MBS never
populated this field.

A newer feature called modularity obsoletes effectively replaces the
end-of-life service level.


DECISION
========

Remove service levels in favor of stream obsoletes.
