Phase four means that a virus has gained the ability to cause community-level outbreaks.

VOA: special.2009.05.06

a medium-term phase out of what they call inefficient fossil fuel subsidies, although this would take into account what they call vulnerable groups and their development needs.

VOA: standard.2010.06.27

But it has taken on new urgency,coming one day after the World Health Organization raised its global swine flu alert to Phase 4 on the six-point scale.

VOA: standard.2009.04.28